Bitcoin Forum

A Danish software company Miracle A/S (http://www.miracleas.dk) has implemented an awesome Bitcoin client for Android called BitcoinSpinner. The developer is not active on this forum, and since it is built on top of the BCCAPI (http://code.google.com/p/bccapi/), and I have participated with testing and suggestions I am proud to announce it here.

BitcoinSpinner is minimalistic, to the point, and is intended for broad adoption.

Features:

• Ready for use right after installation - The block chain is managed by a server.
• NOT a Bitcoin bank - All private keys are kept in app-private storage on your device.
• Send & Receive Bitcoins using QR codes.
• Share your Bitcoin address using Gmail, Twitter and more.
• Backup & Restore your wallet using QR codes.
• It is Open source (http://code.google.com/p/bitcoinspinner/) - Geeks can download the code, review it, and roll their own.

Because BitcoinSpinner does not download and manage the Bitcoin block chain it is ready for use immediately.
This also means that it has:

• Low storage requirements.
• Low bandwidth requirements.
• Low CPU requirements.
• Low battery consumption.

BitcoinSpinner comes in two versions and is available on the Android Marketplace:

• BitcoinSpinner for the production network (http://goo.gl/0P5vG)
• BitcoinSpinner for the test network (http://goo.gl/a4ydJ)

Note that this is a beta release. Use with caution.

You cannot have an announcement like this without a bounty: The first one to post a picture in this thread of their Android device with a scannable QR address code displayed with BitcoinSpinner will get a shiny new Bitcoin.

Your feedback is appreciated!

Interesting!

if it does not download and manage the Bitcoin block chain.

how do you get confirmations?

BitcoinSpinner uses the BCCAPI (http://code.google.com/p/bccapi/),  which connects to a server. The server  holds the block chain, and the public key of your Bitcoin address is uploaded to the server. This allows the server to scan the block chain for matching incoming transactions. The corresponding private key never leaves BitcoinSpinner. Whenever BitcoinSpinner needs to send Bitcoins it asks the server to give it an unsigned transaction comprising of unspent inputs, and outputs sent to the receiver + plus change sent back to yourself. BitcoinSpinner verifies that the transaction only sends to expected receivers, signs the transaction, and lets the server transmit the transaction to the Bitcoin network. More info on the BCCAPI and sources available here (http://code.google.com/p/bccapi/).

Android market tells me it can't find it. I think it does that when a program is incompatible with the device. What are the requirements?

Looks nice!

Android version 2.2 should do it. Just follow the links in the post.

Explains it; my phone has 2.1.

2.2.x and forward cover roughly 85% of the devices out there. As far as I remember the developer mentioned that it wasn't tested on 2.1.x and earlier, which is why it wasn't marked as compatible with those devices. However, it still might work. I'll send him a note and let's see what can be done.

https://i.imgur.com/KgADM.jpg

Here's my photo.

We have a winner! 1 BTC on its way to you.

Please share your user experience.

I got the bitcoin right away ("on its way" to me).  And it was confirmed (http://blockexplorer.com/tx/50ae3892e42357bec996d4dafdd80164115720594756c5935bb8c1a8267a1b58) as I was typing this post.

Update with full review

Compliments:  Very clean, minimalist, simple interface. Very, very fast: so much better than a BitcoinJ-based client (no offense to the creators of BitcoinJ as their efforts are incredible, but this uses mobile phone resources much more effectively).  I really like the QR code-based wallet export, too.

Negatives:  Forces a .0005BTC fee for sending a transaction rather than intelligently deciding whether it's possible to send the requested amount without a fee. No address book.  No way to connect to a different BCCAPI server in the app (if you want to run your own, I can see people using BitcoinJS and/or Electrum servers with a BCCAPI front-end in the future).

Differences that aren't necessarily negatives:  No transaction history, just a balance.  Single bitcoin address only.

All in all, it's very clean and beautiful and probably doesn't need anything more considering the primary use case (paying with/receiving bitcoins in person).  I really, really like it.  It acts like an actual cash wallet, not a bank account.  You know your balance and you pay to the address given to you by the recipient/shop in person.

Simple and effective. Nice work!

Just tried it. This is a great piece of software.

A Bitcoin spinner (http://www.urbandictionary.com/define.php?term=spinner)? ;D

Trying it out at the moment - nice work!

Very nice!  What technology was used to create this?  Is it something very specific to Android or would it be easy to port to the iPhone (and run on a jailbroken iPhone)?

Thanks for the feedback.

Regarding the fee: This is a limitation of the server implementation and not the App as such, or in other words my fault. You are right that you can deduce the minimal fee, which is some cases is zero, by among others looking at the age of your inputs. Etotheipi started a thread on this here: https://bitcointalk.org/index.php?topic=51081.0
For now I have chosen a conservative approach where the fee is 0.0005 * (1+int(transactionSizeinBytes/1000)). I will be looking into optimizing this going forward.
The paramount thing to note here is that it is critical that the fee calculation is not too low, as you may risk the transaction is not propagated through the network or accepted by a miner. In scenarios where you manage your own block chain and end up with a transaction that got stuck you can basically delete the block chain, keep your wallet keys and load it anew, and finally make a new transaction with a larger fee. With the BCCAPI I cannot do this as I don't have a separate block chain per wallet, and don't want to spend the processing power to scan it anew whenever some poor guy sent out a transaction with a zero fee. In the end I would like this to be simple and safe to use.

No address book: This feature is an App feature and independent of the BCCAPI. It may be a good thing to add to the App going forward, but I guess that it depends on the use-case. If we want it to look like your ordinary wallet, then you do not have an address book or a transaction log for that matter. Whenever you pay you grab the money and pass it on to whoever you are trading with. However, the reason why I don't have an address book and transaction log for my ordinary wallet is that the first doesn't make sense and the latter is very cumbersome to manage. With a Bitcoin wallet this is both feasible and practically manageable. As for the transaction list the BCCAPI already has this functionality. It just needs to go into the App. I'll pass this onto the developer at Miracle and see what he thinks.

In the end the goal with the App is to be simple and easy for anyone to absorb, so maybe transaction logs and address books is something that could go into a Pro version?



 

BitcoinSpinner is written in Java, and uses the BCCAPI which is also written in Java. To implement this for iPhone you would have to port the BCCAPI to C/C++ish languages, and implement the UI on top from scratch. This is not a big pile of work, but would take a seasoned developer some weeks. This big problem however is, as you indicate, that this would only be useable for jailbroken devices. So you would never hit the mass market.

I don't really care about the mass markets, I care about me. ;)

What I really want is a native app built using phonegap, HTML5 & JavaScript such that it's maximally portable.  Also, eventually Apple will allow these apps, especially when everyone is jailbreaking their phones to install them.

I haven't looked into phonegap, but I agree that HTML5 & JavaScript (or Dart) is the way to go, however I see two obstacles:
1. You are downloading the app on each use -> you have to trust the site you download it from.
2. You need access to the camera to scan QR codes, and I don't think this is possible on an iPhone

This is the reason for phonegap…it gives you access to things like the camera across all the devices it supports.  All the HTML&JavaScript are embedded in the app you download (not loaded from a server every time…although you could also do it that way).  And, since it is just HTML5+JavaScript, you could easily make a version that works with any web browser on any device (phone, tablet, laptop or otherwise).  You could bundle it as a downloadable app or deliver it from a website (but as you say, you have to trust the website every time you use the app instead of just once on download…although I've seen some proposals to deal with that as well (i.e. side loading the critical key handling code).

I've downloaded it and am trying it out now.

As a minimalist interface, it looks pretty good. There's not much extra going on anywhere in the app to seriously confuse people.

I sent coins to the app, and it correctly showed the amount "on their way". I had intended to keep it open to see if it automatically let me know when the transaction was confirmed, but got distracted and re-opened the app to see the coins in-hand, so to speak.

All in all, this looks like an excellent, wonderfully simple app that should be great for mass market use.

Just installed... This is the simple type of app I love. I will write it up at BitcoinIntro.com!

Excellent!

This makes sense and I'm glad that you're going the conservative route instead of just letting the user specify a 0 fee.  By the way, looking through the code for the BCCAPI, it looks like it's pretty easy to just instantiate it and point it to another server, which means someone with an Electrum or NodeJS server could fairly easily set up a BCCAPI-compatible web API as well and run a service which competes with yours.  This is probably a good thing, though this particular app doesn't let you choose the URL(s) to which it connects.


I realize it's a feature of the app, but I figured I would put it up there as this thread is dedicated to the app, not just the BCCAPI.  I don't think either an address book OR transaction log is absolutely necessary for the use case of an "in-person" wallet (though having both would certainly help you keep track of spending), and it's very easy to use as it is.  Really, it's an amazing piece of software and I've already told a lot of my bitcoin-curious friends about it.  Thank you for all the work you've done on the BCCAPI and helping create this new generation of low-footprint mobile wallets.

By the way, I did a little bit of research on MIracle and it looks like they have a brewery, too!  I'm going to see what I can do about getting my hands on some of their beers.

This already exists essentially (webcoin) see here:
http://bitcoinjs.org/

This is not what is needed on Android if you are interested in mass adoption.

You might only care about you, as you say, but I care about Bitcoin as a widely adopted tech -- and people like to download apps from the market/app store.

So webcoin might be a good intermediate step for the iPhone, but on Android this app is a step forward.

I just tried this app, and so far, it's awesome! Just what was needed. (Although the color scheme and/or UI look is not my favorite.)

Competition is a good thing. So far everything is provided for absolutely free, and that is hard to compete with  ;)

Going forward I am hoping that this service can continue to run on donations. The total donation income for the BCCAPI is roughly a stunning 2 BTC, and my expenses for the servers at Rackspace alone are 50$ a month.


Yummy. Maybe they accept Bitcoin  ;D

I'm testing BitcoinSpinner right now. If I understand correctly, when I want to backup the wallet I need to export the QR code and keep it in a safe place because it contains my private keys unencrypted. 

I would like to know if it's possible to generate the wallet from a seed like you do in the SimpleClient that comes with BCCAPI. I really likes this feature because there is no need to backup the wallet, you just need to remember the passphrase.

BCCAPI is amazing. Keep the good work!

Thank you community for all the support. Help pushing this app forward by

• Rating it on the Android Market. A rating is good, some words even better.
• Offering translations to other languages, by going to http://code.google.com/p/bitcoinspinner/ and contacting the authors. I just heard from Mats Henricson, who offered to make a Swedish transaltion.
• Help us getting even better usability by suggesting feature improvements, a better color schemes, nicer icons, or even coin-sounds when Bitcoins tick in.
• Check out the code (http://code.google.com/p/bitcoinspinner/) and submit patches

Thanks. One way of improving this could be to grab the screenshots, fix them up to your liking in photoshop, and send them to the authors (http://code.google.com/p/bitcoinspinner/).


Thanks. BitcoinSpinner generates the random seed when it is first started, so it doesn't use the "generate seed from passphrase" feature which is available in the BCCAPI. The backup QR code contains the seed that the private key is generated from, so yes, you should print it out on paper and keep in a safe location.

A forum member is working on a different android client based on the BCCAPI where you use a passphrase + salt for generating the seed, just like the SimpleClient. However I am not sure how close this client is for a beta release. Since he is a member of this forum I'll let him decide when he is ready to announce it.

GREAT work, thanks!

Hello,

I'm working on another alternative client Electrum, which has basically same goals like your implementation, but for desktop client (at this moment). I like your job, except this:


Is there any reason why to use some Java-specific protocol? I'm solving "ideal way how to do universal network layer" right now and thinking about some universal "Bitcoin client API" too, but I prefer platform independent protocol. I didn't found any format specification on BCCAPI (is there any?) and I'm too lazy to read Java sources (because I'm not a Java developer), but do you think there's some room for cooperation on making this protocol more universal, not Java-oriented?

The problem is you still have to wait to check if the transaction actually took place.

Interesting.

Java is a programming language, not a protocol. The wire protocol is REST-like HTTP(S), and nothing prevents you from calling the server side from python. The raw API has 7 functions and is well documented with the Java interface declaration: http://code.google.com/p/bccapi/source/browse/trunk/src/com/bccapi/api/BitcoinClientAPI.java

The implementation of the interface is 200 lines of easy-to-read Java code and available here: http://code.google.com/p/bccapi/source/browse/trunk/src/com/bccapi/core/BitcoinClientApiImpl.java

Apart from this there is a bunch of Java classes for transactions and utilities that make it really easy to implement a UI on top of it.

I am not sure what problem you are referring to. Please elaborate.

Congrats! Looks great, I will try it out in a bit.

Re: BitCoinJ and mobile. I fully agree that currently the BCCAPI/Electrum/server side approach gives better performance. I hope we can close that gap over time such that specialized servers are no longer necessary. For instance, using "getheaders" to catch up to the chain head for new users should give dramatically better first-start performance on mobiles, and it's a relatively simple change. That said, offloading everything to the server will probably have better performance and battery usage characteristics for the forseeable future.

Thanks for all the feedback so far. In the meantime a French and Swedish translation has been added by members of the community. Check out the topic on BitcoinSpinner in the Alternative Clients section, and let's continue there: https://bitcointalk.org/index.php?topic=53353.0

Maybe Findeton refers to a problem of sending couple transactions in quick succession? One needs to wait for each transaction to be picked up in a block then retrieve the TX outs again from server-side blockchain?

Yeah, that is a problem with only having one private key. I tripped up on this with StrongCoin too (although a workaround was implemented of allowing a spend to multiple addresses--this makes the problem much less severe.) Allowing multiple spends at once will help BitcoinSpinner too, but considering the simple design, it should probably be something the user has to ask for specifically. Also... while a little confusing at first, it might help to list the change itself as also being "coins on the way" ("change on the way?"), with the balance of the mini-wallet being 0.00 for a while after a spend.

StrongCoin and other alternative clients may have a limitation with change sent back to yourself. With BitcoinSpinner the change sent back to yourself is available for spending immediately, and you don't have to wait for a confirmation. In that regard BitcoinSpinner works like the Satoshi client.

You can do a simple test with BitcoinSpinner where you:
1. Have  zero balance in BitcoinSpinner
2. Send 2 bitcoins to BitcoinSpinner in a single transaction
3. Send 0.9995 BTC to another client two times right after each other with no intermediate confirmations.
4. Wait for the funds to arrive in the other client.

I see. That's great then... another plus for BitcoinSpinner.

(I checked the last StrongCoin transaction I sent earlier today, and while it worked, it seemed a bit confusing as to exactly why it crafted the two (!) transactions for my single transaction in the way that it did...)

Can you put up your own server?

today i moved 0.5 BTC from my laptop wallet ->Spinner->mtgox->Spinner-> back to wallet all no problem.  Nice and easy.

Hey! Why did I not know of this?

I might owe the authors of BCCAPI/Bitcoinspinner at least 20 BTC. Still have an old bounty on Android client, and the Schildbach wallet never qualified (ridiculous crash-and-bug party), nor did the other one.

No local block chain, but keys? Great concept! The question of key backup remains... check! Very good, I am testing the application right away!

I assume the API and client are made by different people? Oh wow, free with permissive license, awesome!

This is an excellent development! I tried it yesterday, sent some coins from my Schildbach wallet to spinner, sent coins from spinner to my friend's spinner, everything worked perfectly.

It's clearly a work in progress though. There is no way to create a new Bitcoin address, no address book, no way to see sent and received transactions etc. But the core functionality is solid and the idea is excellent. It's very fast to use. Please keep developing it. I'd be happy to donate something to the developer if there is a donation address. ;)

To Vandroiy: the Schildbach client is still the most advanced Bitcoin client for Android and it's fairly bug-free these days. It's regularly updated and works quite well.

I don't really know which client I'd like to use more right now, Spinner is faster because there is no blockchain download, but the Schildbach client has a much better set of features. Probably the Schildbach because the blockchain issue isn't a big one if you remember to download it once or twice a week. If it's at most 1 or 2 days behind, the download is fast enough to be acceptable in any situation.

I installed it just now and sent 5 BTC. Works immediately. Very small footprint, minimalistic but functional. Will do some testing and other phones, probably this week.

This is likely to be my new favorite and the winner in my search for an Android client that started some 6 months ago.



lol... just now, I updated Schildbach wallet to check. Crashed on start. I actually uninstalled it now that I have BitcoinSpinner; unless this one makes trouble as well, my choice is made. Nexus One CM7, the best standard Android environment I know of. Not that I haven't tried it on three other models. The program is just bad. It produces the kinds of errors that just do not happen when people know what they're doing. I can hardly list the amount of absurdities I've faced or seen others face using it. "Deleting Dalvik Cache destroys program", "Crashes after start", "Program no longer found", "Transactions do not sum to balance"... even the error report function crashed along with the rest of the progam.

I know all the phones in question, they range from HTC Magic and Legend over multiple Nexus Ones to modern newcomers; no general trouble with Android software. Just the Schildbach wallet misbehaving on every one of them, throughout different versions of OS and wallet.

No. I'm not paying the bounty to Schildbach unless I can actually use the program. BitcoinSpinner now has a head start; if it shows no errors, it's the winner in my opinion and gets a little donation/old bounty.

Oh wow. When I try to type a number of Bitcoins to be sent, it is always input twice. I can only sent 11, 22, 33, 44, 55, ... BTC. lol ::)

The last person rating it on the Google Market has the exact same issue. Just tested on another phone, again the same issue. Both phones using CyanogenMod 7.

Okay, race is on again. Who fixes first? :)

I don't care who gets the bounty, but I can say that the buggyness of Schildbachs wallet isn't universal. I've been using it with absolutely no issues for a while now. And I know at least a couple of others who have also used it without any major bugs. And they have different devices. My device is Huawei U8800 with Android 2.2.1, btw. This is getting a bit off topic though, but I'm very surprised that you've had such a negative experience with that wallet, because the experiences me and my friends have had are totally different.

Have you reported on the bugs? Andreas seems to be an active developer, the wallet has been updated fairly regularly. I'm sure he would like to tackle them.

@Technomage, yes, multiple people sent error reports. As I said, four different models, at least five devices, and I don't think they were all on Cyanogen. But this is somewhat off-topic, and I don't really care about the story if BitcoinSpinner solves it all.

Which means I'd like the double-digit typing fixed, and maybe I'm totally happy already with that! Yes, an address book would be nice, buy hey, I can copy-paste, so any text editor does the job. I really want nothing more than a minimalistic, QR-ready Bitcoin wallet with private key backup function. And this is apparently being made with BitcoinSpinner.

Fix please. Pretty please? :)

some like me like to have an application, that doesn't rely on an foreign server. i know it's "safe", but a dependency. so, there will always be demand to this other type of app.

said that, i don't like both apps. the schildbach one works (not counting how it didn't work a few month ago), but right now, for example there is a transaction listed with a double negative sign. on idea how i managed to do that.
the bitcoin spinner app just looks terrible and has no additional features that i would like to have.

the schildbach ui on top of the bccapi would be a nice mix for now i guess.

Yes, this is OT, but I have similar issues with Bitcoin Wallet as Vandroiy (HTC Desire S). It's strange that sometimes it works (for example I made a lot of payments during Prague conference with it), but sometimes it's almost unusable. I sent a lot of tracebacks back to Andreas, not sure if it was usefull for him.

Back to topic - yes, Bitcoin Spinner is working for me :-).

I have a problem with it. When I try to send some bitcoins, typed numbers in amount to pay are duplicated. Example: I type "2.12" and get "22.1122". I see somebody else commented on android market with same problem, hope this will get resolved soon.

I like this app a lot!

It does crash now and then though, on my Samsung Galaxy S Plus. Nothing is lost during a crash, so it's not too bad.

The light-weight'ness of BitcoinSpinner is possible because a server that manages the block chain. It is always important to have a broad selection of apps. I guess it is not possible to have a one-size-fits-all kind of app for Bitcoin.
Both apps are free and open source. If there is something you don't like you can help us all by improving it. Here is a list (https://bitcointalk.org/index.php?topic=52674.msg631393#msg631393) of suggestions on how to participate.
The sources are here: http://code.google.com/p/bitcoinspinner/
You can follow the link and contact the devs.

If you don't care about:

• being able to backup and restore if you loose your device
• being able to use the app right after installing
• being able to spend change sent back to yourself without waiting for the next block
• having an app that has low bandwidth, memory, storage, CPU, and battery requirements

... then BitcoinSpinner is not for you.

I agree.

I have PM'ed the developer regarding the double-digit issues and crashes. I assume that a fix is around the corner.

I know I know. I've also already coded one or two android apps (nothing serious, but I'm at least familiar with the framework) and both apps are on my radar.

There is a fix out that should deal with the double-digit problem. However, the dev tells me that he cannot reproduce it on his devices physical or virtual, so please verify the fix and report back to him directly. I have told him that he should consider joining the forum as there is an old 20 BTC bounty that he might claim  ;D

The fix seems to have taken care of the issue on my phone.

The BitcoinSpinner developer has joined the forum and is lurking in the newbie area: https://bitcointalk.org/index.php?topic=20292.msg642928#msg642928
How do I accelerate his white listing?

Yep, fixed!

Wild guess: PM the admins of that subforum: RylandAlmanza, trentzb, SomeoneWeird, MiningBuddy

https://bitcointalk.org/index.php?topic=53932.0

Since we're back at using centralized solutions, we might aswell drop bitcoin and go back to classical banking.

How does something like this represent the idea that bitcoin stands for?

I understand the point of the blockchain not being on the phone, for storage and bandwith reasons.
The arguments i hear most are outdated i think.
-Most new smartphones have at least 16GB internal storage.
-You don't download the entire blockchain over the mobile network, use wifi for that and only mobile for transactions and updates.

And yea, i know your phone may have only 512mb of storage, but that doesn't matter for now since the masses of people ain't gonna use bitcoin for at least another 5 years, IF it ever gets off the ground in the first place.
By then, smartphones will have 1TB storage and at least a 10mbit mobile connection, so yea, we can keep it decentralized!

[edit]

Ok, this is what i see is a potential problem.
This bitcoinspinner company wants to make money.. but oops, the app is free. (ofcourse it, is, and always will be, you'll be paying with personal information from your phone)
So, they invent the system all over again, they will start to lend out non-existing bitcoins to users, at a nice rate.
Where do those bitcoins come from? Well, from the other users that have plenty balance, unless everybody wants to spend all the money they have at once, they will be doing fine, just like the banks!

The 'you own the keys' argument doesn't really hold up imo, after all, you 'own' your creditcard too, still the company manages it and in the end has ultimate control over it.

Don't like it, don't use it! You have other fully decentralized android clients...
For people like me though, light clients are the future!

True ofcourse, i did test it, and it works fine, i can't complain about that.
I'm just pointing out some serious concerns i have :)

Take a good look at the scalability section (https://en.bitcoin.it/wiki/Scalability) of the Bitcoin wiki, and lets assume that 5 years from now Bitcoin is broadly adopted. Blocks will be measured in the gigabytes. Let's see how your mobile thingy will cope with that.


For some reason it seems that you think that every company is evil. There is nothing I can do about that I guess. But there is at least one thing that you have misunderstood. Because the private keys never leave the app there is no way that the server can spend your coins or give some of your coins to other users. The 'you own your credit card' analogy you propose is ridiculous. If you don't trust the app that you download on the Android Market you can download the sources, inspect the code, even make your own fork, and roll your own.

Another thing... The only privileges that BitcoinSpinner requires are NetworkConnectivity and View Network State (you are notified about thins when you install the app). This means that it cannot loot your contacts or other personal information.

At the end BitcoinSpinner is not for everyone, and it is good that there are other options out there. BitcoinSpinner, like the Satoshi client itself, is a piece of beta software. Let's learn and improve...

If you own the keys on your phone, then the server doesn't have them. Ergo, they can't do fractional reserve banking.

Around 10 days ago, I had a look at BitcoinSpinner working on the mobile phone of a work colleague. I really liked what I saw. He installed it in a few seconds and got his first funds from the Faucet just as quickly. I must say, I was pleasantly impressed. At the time, I could not understand how all the process was performed so swiftly, since I was expecting the whole block chain to download on the phone.

I don't know if future versions of Bitcoin clients will only download the strictly necessary transactions, or whether they will query peer nodes online for block chain information, or any other alternative. In any case, for the time being, a really clever and clean solution by BitcoinSpinner.

Come back with an argument as to why this app is broken when you understand how the private keys in Bitcoin work.

There is a certain issue with trusting the balances coming in (if for any reason the server providing the data is motivated to lie to you and tell you a fictitious transaction confirmed when it has not, there's no way for you to tell that happened without the blockchain), but beyond that there's very little harm that can be done with such a "centralized" solution.

Again, the great thing about Bitcoin is not that it has to be decentralized, but simply that it can be. You can be your own bank, your own currency exchanger, etc. Or not, if you simply don't give a shit about those things.

A solution like this can still be very decentralized. It's possible to have a lot of BCCAPI servers, all over the world. And even if someone decided to ddos all of them, it's not a huge problem. The actual bitcoins are still safe because the user has the private key, no one else. That key can be added to a regular, totally decentralized client, and the coins are usable again.

But I don't really get the blockchain discussion, there are many solutions for scaling Bitcoin. The Schildbach client (which doesn't have a server-side) uses a blockchain file which is currently about 20 megabytes. With that technique the file is probably decent size even if Bitcoin gets wider adoption, scaled to the smartphones of that time, that is. But the thing is, BitcoinSpinner is still faster and more convenient even though the compressed blockchain format is only 20MB.

I think both methods can work side by side and it's not only the mobile world that has this problem. Desktop clients are JUST AS SLOW as the mobile clients that have a compressed blockchain format. It's the same. I see demand for this kind of setup in both desktop and mobile worlds.

there is a decentralized, open-source alternative to BCCAPI. it is called Electrum: http://ecdsa.org/electrum

At this time there's not an android app for electrum backends, but friend of mine is working on it.

Your friend might be on to something big. I'm looking forward to testing it. I think it's important that the server code is open source and anyone can run it. That will make it much more decentralized. Then we can have security, reliability and speed in one neat package. Hopefully a good UI as well :)

Nice! Remind him it should be just as simple as BitcoinSpinner :)

The input bug is fixed! Yipee! I will now test it for a bit. If it works, I'll donate at least 10 BTC to API and Client each, and would have finally gotten rid of that ancient bounty.


Concerns that make no sense. Just check the sources and BlockExplorer if you want to be certain they do not cheat. Except if the Netherlands guys hacked your personal DNS server and simulate blockexplorer... ya right, of yourse. ::)

The concept is secure. Feel free to check the implementation etc, indeed that can have backdoors like always, but the design sounds perfect.

I thought I might say hello now that I have watched your comments and listened to them.

First I would like to announce that version 0.3.0b is out with Transaction history.

Second I would like to thank all of you who have tested, commented and rated the app. If you keep using, I'll try to keep updating.

I'm glad that You like the app, but regarding the design of the UI, I'm an engineer, not a designer, so if someone would take the time to enhance the face of the app, don't hesitate to help!

Works great for me.

I love the fact I can back up the wallet once after I start the first time and it is always backed up. I assume my phone could be thrown into the ocean and all I have to do is buy a new phone, download the app, and restore from my original wallet-backup and all my coins would be there on the new phone. Wow.

I will say that during our meetup last night in Orlando, BitcoinSpinner was the best mobile wallet.  

A new person hot girl showed up at the meeting (NOT a techie by any means), and within 1 minute she had the app on her phone, and I sent her $20 worth of bitcoins in exchange for $20 cash.  

The incoming deposit showed instantly on her phone as pending, and was credited in about 5 minutes.

She was able to pay her check at Whiskey Dicks using the app, and the speed at which she was able to scan and send was good.

More importantly, the speed on the back-end of BitcoinSpinner was most impressive.  Once the send was confirmed in the UI, the coins were actually sent on the bitcoin network and received by Bit-Pay in about 1 second.  This compares to a typical 3-5 second process time to do a withdrawal from the MtGox Mobile Wallet.

Keep up the good work, and whatever you do to the UI, don't delay the back end processing.  You have the best wallet on the market for that.

LOL!  this is so hot on multiple levels! ;)

Pics or it didnt happen!   ;)

This gives me a warm fuzzy feeling.
During Christmas I have been working on improving BitcoinSpinner (Yes, I have joined the BitcoinSpinner dev team). In the upcoming release we will improve on the reliance on network connectivity. Right now you cannot start BitcoinSpine without internet connectivity or the server back-end being up.  This is really bad if I for some reason choose to discontinue the BCCAPI server, and you haven't done a backup of the private key. The next release will have a slick & swift asynchronous back-end, which allows you to see your balance and/or backup/restore/export your private key without a connection to the server. In my mind this is the final excuse for not using BitcoinSpinner as your day to day wallet.

Cheers & Merry Christmas
Jan 

Maybe a dumb question, but will it be possible to switch servers from within the bitcoin spinner app? Or even better, specify a set of independent servers, which all are just a synced copy of the same data, and it doesn't matter if one goes down? I don't know all the details, maybe that's not possible.

i use Spinner on an Android.  can i be confident you will push updates to me as they come out?

Right now there are two servers running at Rackspace, one for the Bitcoin production network and one for the test network. Servers cost money, but if BitcoinSpinner catches on big time I will put up loadbalanced/redundant servers. Right now there are about 250 clients installed out there, and rarely more than a handful running. At the current usage the servers have absolutely no problem keeping up.

Yes. Whenever there is an update it will be available on the Android Market, so you just have to update the app on your device. I'll also post on this topic: https://bitcointalk.org/index.php?topic=53353.0

Jan, it would be awesome to have the BitcoinSpinner as a native iPhone app.  Apple has now opened the door to bitcoin wallets with Bitpak, but that app sucks.  I can tell you that from what I see here in the US, everyone (and i mean everyone) has an iPhone.  Androids are rare amongst the non-hacker crowd.

You are right and I totally agree.
Apple accepting Bitcoin clients apps is really big news. However, I have no experience with iPhone apps. My domain is more Java'ish and crypto stuff. My hope is that someone in our community with iPhone dev experience takes up the challenge of porting BitcoinSpinner to iPhone. I am willing to help in any way I can.

dont let your personal experience fool you.
market share by OS q2 2011:

http://upload.wikimedia.org/wikipedia/commons/b/b5/Smartphone_share_current.png

doesnt mean iphones are not important, but the priority should clearly be android. since in general android phones are cheaper they will continue to spread faster.

fornit I've seen the charts but I honestly don't believe it.  I see Apple everywhere when I walk around.  When I look at the site statistics of people visiting my website from their mobile phone, here's exactly the stats we see:

http://i59.photobucket.com/albums/g296/tonygal/2011-12-30_1729.png

the statistic i posted was sales, not phones in existence.
even if iphones are still much more common in the usa, i am pretty sure this will change over the next few years. anyway, i agree that it would be good to have an iphone version of bitcoinspinner. its clearly the best application for mobile devices right now. bitpak is absolutely no alternative.
 

yeah, but the types of ppl you walk around and visiting your website are all Hotties  ;)  they all use iPhones.

I imagine Apple users are desperately looking for an alternative way to pay to avoid exorbitant fees.

ah, yeah you got a point there...:D

+1


Agree mostly. Sales stats are misleading. I've sold/repaired phones for 7 years. Free and cheap (price wise) phones like many Android models are damaged and lost more often, and replaced, adding to sales numbers.  More expensive (not necessarily better) models like iPhones are usually better kept and repaired vs replaced.  Usage data like Bit-pays are generally more accurate.  Either way iOS needs an app and Bitpak is not it.  And don't forget Apple users tend to spend more per device on phones/apps/rate plans - though Apple does take a nice cut of that.  It would be great to have the same app on both OS's and see sales/use data.

BitcoinSpinner (BCCAPI) works for me, so I have the ancient 20 BTC Android bounty to pay. The client program crashes frequently, and takes long to initialize at times, but it serves its purpose and I've not had any serious issues.

That said, 15 BTC are going to BCCAPI. It's funny the donation address is not shown as QR code on the page, I had to mail it to myself and paste it into BitcoinSpinner. :P

That means I should send at least 5 BTC to the BitcoinSpinner developers, but I didn't find a donation address. Do they have one? ???

This is my experience too.

Thank you for the 15 BTC!

Not having the donation address as a QR-code is a blunder on my behalf. The BCCAPI (http://code.google.com/p/bccapi/) page has been updated with one.

The BitcoinSpinner developer is not very active on this forum, but he has included a donation in his signature. Here is a sample: https://bitcointalk.org/index.php?topic=52674.msg644862#msg644862

An update (v0.4) is in the pipe, which changes BitcoinSpinner's backend communication to the server. This should remove crash issues. I expect the update to go out tomorrow. I also experience that it takes long time to initialize at times, especially when my device has been idle for some time. I think the reason is that the device has to fire up its wi-fi, and this takes time. The good news is that the next version allows you to start up without a network connection, and see your "old" balance. This also means that you can backup/restore/export your private key when in off-line mode.


The reason why it sometimes takes long time to initialize something I also experience if

This is awesome, I got it to work on my android modded HP touchpad, unfortunately the camera doesn't work with android installed, so I can't scan qr codes

But on the plus side I can make HUGE qr codes, heres a photo with a floppy disk for comparison
https://i.imgur.com/NIIoM.jpg

Ah, okay. Sending 6 BTC. The app crashed on first start attempt when I tried to send the coins, so I only tipped 1 BTC on top. Expensive crash. :P

Fortunately I have good news. Just before Christmas I joined the BitcoinSpinner dev team. Previously I was (just) making the BCCAPI, and during the holidays I gave BitcoinSpinner a major swing. This should greatly improve user experience with no or poor network connectivity.
Please upgrade to the latest version (0.4b) on the Android Market place.
More details on new features here: BitcoinSpinner in the Alternative Clients section (https://bitcointalk.org/index.php?topic=53353.msg672264#msg672264)

Great job. Very well done. +1 for an iPhone client.

I wouldn't worry too much about "seeing Apple everywhere". Every iPhone looks nearly the same and they all have very prominent branding so it's easy to spot them quickly.

And besides, I agree that data can provide insight. Bitcoin is a long term project. The state of the mobile market today is not relevant because Bitcoin itself is not relevant today. What should interest us is how things might look in two or three years, and how it breaks down amongst different demographics.

Apple long ago stopped announcing activation figures for the iPhone specifically (tablets aren't so relevant for mobile payments), it's likely they are a long way behind. The last announced Android figure was ~700k per day. I think Apple stopped announcing at 250k per day (for both tablets and phones).

But we can try and extrapolate from other sources. Clicky is a newish web tracking firm with half a million sites. StatCounter has about 3 million. The mix of sites is of course NOT a random sample of all websites mobile users visit, so we use two sources to try and discern general trends rather than absolute figures.

Firstly, we can see that a lot of this varies by region. For instance in South Korea Android utterly crushes iOS. I didn't include Clicky because their graph for Korea is wildly oscillating noise and I doubt it's reliable. StatCounters data matches recent news reports where lack of LTE is cited as a common concern.

  http://gs.statcounter.com/#mobile_os-KR-monthly-201012-201112

In Germany the iPhone is more popular but it's changing quickly and soon the positions will reverse:

  http://gs.statcounter.com/#mobile_os-DE-monthly-201012-201112
  http://getclicky.com/marketshare/de/operating-systems/mobile/

Switzerland:

  http://gs.statcounter.com/#mobile_os-CH-monthly-201012-201112
  http://getclicky.com/marketshare/ch/operating-systems/mobile/

Clickys results are a bit dodgy looking again, but they both agree on the general trends, iOS is way ahead but Android is growing, market share changed permanently in August.

The iPhone launched first in the USA, it's made by a US company, and it's a fiercely fought market with huge marketing budgets. So it's not surprising that the situation there is not changing so fast:

  http://gs.statcounter.com/#mobile_os-US-monthly-201012-201112
  http://getclicky.com/marketshare/us/operating-systems/mobile/

Instead both Android and iOS are selling enough to keep pace with each other in a rapidly growing market, and Blackberry is dropping like a stone (as a fraction of overall web traffic).

The situation is more interesting in the developing world, which I think is somewhere Bitcoin could be of more impact than in the west - flaky inflation-prone currencies and lack of good credit card systems are common issues there.

Brazil:

  http://gs.statcounter.com/#mobile_os-BR-monthly-201012-201112
  http://getclicky.com/marketshare/br/operating-systems/mobile/

The stats are harder to read here, probably due to lack of sufficient data and different mix of sites with the tracking code installed. Clicky shows iOS keeping stable and Android growing steadily until a massive jump at the end. But the numbers are questionable - is iOS really more popular than "other"? I doubt it, more likely Clicky, being newer, is installed on sites that are more modern/web2.0/tailored for smartphone users. Also there's no volume counts, it's probably low. StatCounter shows a slightly more believable graph in which both iOS and Android are behind Symbian (cheap nokias), but this time Android is ahead. The derivative changes changes in September which is the sort of thing you'd associate with a new device launch.

Estonia (does it still count as 'developing' these days I wonder?)

  http://gs.statcounter.com/#mobile_os-EE-monthly-201012-201112
  http://getclicky.com/marketshare/ee/operating-systems/mobile/

Clicky shows the exact opposite of StatCounter here, but the graph is so noisy I suspect it's being drawn from hardly any data at all. Clicky isn't even translated into Estonian. StatCounter, with a large number of quite old sites, is more likely to have good coverage in smaller geographies, and they show Android clearly dominating.

Russia is an important market for Bitcoin:

  http://gs.statcounter.com/#mobile_os-RU-monthly-201012-201112
  http://getclicky.com/marketshare/ru/operating-systems/mobile/

Again, divergent data. Clicky shows Android growing and iOS leading. StatCounter shows Symbian way ahead and Android growing, iOS shrinking.

So the general conclusions are:

• Source selection can change your results completely.
• Interesting longer-term markets for Bitcoin are showing a consistent trend towards Android, which is good for us.
• The situation today in mature markets like the UK and USA is Apples to lose, but unless they change the game again it seems likely they will do so - mostly their sales are keeping pace with market growth but Android sales are outpacing it, often at the expense of older devices.

I've lately been enjoying an Android 4 phone. The new GUI closes the gap with iOS in responsiveness/frame rate and slick looks, which was one of Apples key advantages. So I think these trends will become even more pronounced over the next couple of years. This is good for Bitcoin because Apples policies are very inconsistent and it's unclear if BitPak and friends will be allowed on the platform long term. Also, NFC makes for very nice mobile payments and Apple doesn't seem in a rush to support it.

thanks mike, nice overview! also, for my country AT it shows quite the opposite. however, i think there is still room for surprises … android will really become dominant, once all non-smartphones have vanished and very cheap models with probably older 2.X versions (or then, 3.x) are what users get if they want a new 0 €/$ phone. That will also the type of model you will see in developing countries. And don't forget, mobile data is in some of those 3rd world countries cheaper than in the US!

Fixed that for you.

EDIT: reference http://www.wired.com/gadgetlab/2011/12/ios-revenues-vs-android/ (http://www.wired.com/gadgetlab/2011/12/ios-revenues-vs-android/)

Hi, today I tried to use BitcoinSpinner. I have 0.9957 BTC on my wallet (confirmed), but I'm unable to spend any money from the wallet, because "Send Bitcoins" button is disabled even when I put 0.1 or 0.01 as "Amount to pay". Any idea?

Hm, is there any reason to drop private keys after uninstallation? I tried to reinstall BitcoinSpinner and now I have nice clean wallet ;-).

As an example, bitcoin wallet using bitcoinj is keeping private keys untouched so I can uninstall and install application as I want. Well, I expected that BitcoinSpinner is doing the same. But I see "Use at your own risk", so this is just a recommendation, not a complain...

https://bitcointalk.org/index.php?topic=53353.msg680479#msg680479

vuce, thanks for link. But looks like Monday release isn't there yet ;-).

BitcoinSpinner uses private app storage, which is wiped at uninstall. However, this also has the nice feature that other apps cannot get to it, which is paramount. Another nice thing is that BitcoinSpinner only needs network access privileges. This lets you know that it does not try to snag your address book or keys from other apps using SD card storage.

Yep, that will be next monday. Read the rest of the thread for the embarrassing reason ::)
To sum up, you cannot spend BTC if your balance is <= 1 BTC because of a UI bug that disables the Send button. I kneel in the dust, it is my fault sire.

Oops I broke the rule of three posts in a row.
Whenever you install BitcoinSpinner you should make a QR-code backup (Click Options button -> Settings -> Backup Wallet). This is a one time operation, which lets you restore the wallet at any time on any device. In short, killer-feature. I'll add a visual reminder which is shown right after first launch in a coming release.

is this a backup of both pub/priv key or just priv key?

Its not very useful at the moment IMO. It shows a QR code, but that it. Which means I have to use another smartphone or something to make a picture of it. It would be better if I could save that code somewhere, bluetooth it, whatever. Perhaps even mail it I want it on my main pc, otherwise I cant print it.

It is a backup of a random seed that allows BitcoinSpinner to deterministically generate keys.


There is a 'Copy to Clipboard' button, which puts the textual representation of the seed on the clipboard. you can use this to regenerate the QR code using for instance http://qrcode.kaywa.com/

Personally I use a digital camera and take a picture, which i then print out. It's a bit cumbersome, but I haven't found a way to print directly from my phone.

Where? I dont seem to have any (android 2.3).

right under the QR code itself

I can confirm I have NO copy to clipboard under the qr code. I'm on 2.3.4. It must be a bug.

Last time I installed qtqr on my laptop to scan the phone with the laptop's webcam. Now go tell my girlfriend that bitcoin is simple to use. :)

let me be more specific; click on menu, then settings, then backup wallet, verify with Yes, QR code pops up with Copy to Clipboard directly underneath.

this is what I see.

http://db.tt/gM4taKBJ

did u run the recent upgrade?

i have Copy to Clipboard directly under that QR code.  strange.

Could it be an issue with screen resolution? My phone has a relatively low resolution (320x480), maybe there is no room for the button?
Whatever the reason, I have the same as dunand. No copy button. App is up to date.

It may be caused by the resolution, but I doubt that as there seems to be room enough to render it. One of the problems with Android apps is that there are so many different versions and mods that it makes it hard to verify on all combinations. This is something I'll have to investigate.

May I suggest you make a menu for that screen (menu button and/or long press on the QR) that allows to save the image, send the image (bluetooth) etc?

The solution might be to change this to a real activity instead of just a dialog, and add more options as you suggest. The problem with writing it to an SD card is that this would require the app to have more privileges, and I kind of like that it right now only needs Network access. This allows the user to have more trust that the app does not mess around with stuff it shouldn't, and prevents the user from by mistake leaving the image on the SD card for other apps to snag. Thanks for the suggestion, I'll have to think about this.

A "send to" dialogue wouldnt require any extra privileges I think. 

Also, a question; is there a way to share wallets between bitspinner and the regular bitcoin client?

Right. This is used with the Bitcoin address on the main page already. This allows you to easily share the textual representation of your Bitcoin address by clicking it and chose for instance send email. However, I don't think I can share a bitmap this way.


Yes. you can export your base-58 encoded private key (Option button, Settings -> Advanced -> Export private key) and import it using pywallet or the satoshi client with the import private key patch. This way you have the same private key in BitcoinSpinner and in your satoshi wallet. (There is no way to do an import the other way around.)

Sorry to say, but still no copy to clipboard button on my phone.

edit: wrong thread, but point still stands :)

The "cannot send less than 1 BTC" bug has been fixed is the latest update which also has a bunch of new features. More info in the Alternative Clients (https://bitcointalk.org/index.php?topic=53353.msg696505#msg696505) section.

Jan, thank you for fixing the subBTC bug, it works for me now.

Thanks Jan.  I gave about 50 demonstrations of sending bitcoins at CES and I used your app the majority of the time.  It's very simple and very fast. 

it is also included in the deposit card video demo.  I gave this same demo in person to people all last week at CES.  it is pretty cool when the phone goes "cha-ching" with the text message alert a few seconds after I send the money from your client. Thanks for fixing the 1 BTC minimum.  I had to keep reloading my wallet at the show so I wouldn't run out of money during the demos!

http://youtu.be/3UmynaPg8hw (http://youtu.be/3UmynaPg8hw)

whats this about a "ka ching"?  i just received 1 btc and didn't hear anything.  is it only for sending?

it's a bit-pay thing, not the Spinner.  At least how I have it setup.  Whenever you receive a payment to your Bit-Pay deposit card, an SMS is sent to your phone.  I happen to have the sending number stored in my iPhone with a "cha-ching" alert tone for incoming messages.  BitcoinSpinner was just sending the transaction.  Watch the video, you'll see :)

yeah, it did the same to me for several openings but now is working properly  ???

haha.  just tried it again; black screen for 5 sec then flipped to home screen.

it did seem to get better after i sent 1 BTC to it the other day. :P

There is a known initialization issue which kicks in when leaving the app running in the background on low end devices. I am traveling this week, but have a fix which i will submit once properly tested. Sorry for the inconvenience.

BitcoinSpinner is the current leader in smartphone apps. I will recommend this app to my tech literate associates.

This has now been fixed in the latest update (0.4.5b), confirmed both by Holliday and cypherdoc (thanks). More info in the Alternative clients thread on BitcoinSpinner (https://bitcointalk.org/index.php?topic=53353.msg714310#msg714310).

This is an awesome demo! Thanks for sharing, and for demoing BitcoinSpinner at CES.

BitcoinSpinner is great, good work!

I think one really simple change would make the app look much better and more professional though. Change that orange color to black. =)

I hear you  :)
I am not really good at graphics design or choosing colors. So please help me out by:
Taking the screenshots here: https://market.android.com/details?id=com.miracleas.bitcoin_spinner
Open them in your favorite bitmap editor, change the colors to your liking, and post them in this thread: https://bitcointalk.org/index.php?topic=53353.0
Then I'll apply it to the code if folks generally like it.

This just happened on my Galaxy S2, so it's not limited to low end devices ;)  That said, I am running a modded ROM for ICS, so that's probably not helping :D

hello Jan,

can you please add to the app that the amount of bitcoins are shown in EUR also ?
thank you

may be as an option ?

greetings
pazor

I am not able to reproduce this myself. Help me fix it by answering the questions in this thread: https://bitcointalk.org/index.php?topic=53353.msg747989#msg747989

Hi pazor,

It is on my list, but it may take some time before I get there.

1. Bug fixing
2. Address book
3. Transaction history improvements
4. EUR and other currencies
5. Relax and drink beer ;D

Cheers,
Jan

In the Linode security breach trust given to their proprietary infrastructure was violated and bitcoins were stolen.

I'm wondering if there is a similar vulnerability with a mobile platform.  I read in the Android how-to for publishing an app that only an app signed with your private release key will get pushed out as an update.   What if, however, your system used for building was compromised and an attacker were to get your private release keys to build a rogue update (that stole bitcoin private keys).  If that roge release were published to the marketplace nobody would likely notice a problem until after the attacker already would have a lot of private keys!

If I were storing an amount of bitcoins worth worrying about, I might then want a way to disable the automatic update of this app.  Is that possible?

Also, might there be an announcement here for when you publish, maybe signed with your PGP key, which includes a signature for the release to be published to the Android Market?

I know this sounds paranoid, but crazier things have happened before, right?

These are all valid concerns. Hacking bitcoin related services has turned out to be quite profitable.

Android apps are not automatically updated by default. This is an option that you can enable on your device, but I recommend that you don't.

Whenever I update BitcoinSpinner I announce it in this thread: https://bitcointalk.org/index.php?topic=53353.0
However publishing a signature on the APK with a different key doesn't give you much, as you (as far as I know) cannot retrieve a hash of the application from the Android Market. If you are really paranoid you should download the sources and roll your own. This also allows you to review any changes that have been added since last release.

(By the way, there is an update in the pipe which adds an address book and launching the send page from a Bitcoin URL)

The latest BitcoinSpinner update is announced here (https://bitcointalk.org/index.php?topic=53353.msg786680#msg786680), and includes the address book feature that you requested. Transaction history has been there for a while. Did I mention the in-app donation option?  ;)

I tested it a while ago, so you should have gotten some spare coins at least once  :-*

Looks great. I like it. Two connected suggestions though. First, make it easy for the user to empty their wallet. I always appreciate when I go to make a payment on something and it gives me a box to type in the number and instead of making me remember the amount, it allows me to click something that autofills it. I would suggest something similar here. Allow the user to press the balance to autofill in the amount to send. Second, I think it would be interesting if at any time the balance becomes zero, you give the user the ability to create a new wallet and forget the old one. I don't see a way of doing that right now.

Excellent job.

edit: sorry, I see now that you have a dev thread as well. On which thread would you prefer people offer feedback?

I'm on android 2.1 here I guess (pretty old phone with low ram, don't think I can update)

What's keeping BitcoinSpinner from running? Android Market says "incompatible with your device"

Two small inconsistencies:

• When showing the BTC amount in the wallet, dot is used as the decimal sign. But when showing the amount in regular currencies, comma is used as decimal sign.
• When showing the BTC amount in the wallet, the currency is displayed after the amount. But when showing the amount in regular currencies, the currency is shown before the amount.

Nice finds. For regular currencies BitcoinSpinner uses the decimal separator defined by the selected locale (US uses '.' DK uses ','). However for BTC '.' is always used. To clear confusion I have decided to use '.' everywhere in all locales.

Both items will be fixed in the next update.

I have only built/tested BitcoinSpinner on 2.2 devices. After a few modifications I can successfully build it against 2.1.
2.1 will be supported in the next update  :)

Please post technical stuff and bugs on the dev thread (https://bitcointalk.org/index.php?topic=52674.msg628527) and the rest here.
Thanks, Jan

wooooo! you're the best!

Hi there,

I'm on android 4.0.x with NFC, would this be useful as an payment security device for Bitcoin Spinner?

https://store.yubico.com/store/catalog/product_info.php?products_id=72

intersting! thanks for pointer.

This is an interesting piece of hardware for authentication purposes, however this is all it does. (You cannot offload your Bitcoin private key onto it). You can use it for generating one time passwords if you for instance want to authenticate yourself with some service instead of (or in combination with) using a password. This would be a great thing for Bitcoin banks such as Paytunia or MtGox.  (MtGox already uses a yubi device).

BitcoinSpinner is different. The server side does not have your private keys, and does not control any Bitcoins. It just serves as a custodian of the block chain. Your private keys ONLY leave your Android device if you choose to make a QR-code backup/export.

If the server side of BitcoinSpinner was hacked, full breach, and left as a burning wreckage (you know, Bitcoinica style), then what would happen:

• The hacker would find the block chain, a bunch of Bitcoin public keys + bookkeeping information in a database, and a server log (which does not contain your IP address). This is all useless stuff.
• I would be pissed, as I would have to spend time on getting the service up and running again. This would probably take a few days, as I would have to make sure how he got in etc.
• You as the user would safely walk away from the wreckage with all you BTC even if you did not export your private key before the hack. BitcoinSpinner allows you to launch the app with no server connection and do the export offline. Once you have exported you could import your private key into one of the other excellent Bitcoin services around.

The security of the server side isn't the problem here. Many (including me) would like more ways to secure the user side. Yubikey could be used to help with that. Server side security doesn't help if your phone is stolen, it's basically a race against time. If the thief knows about Bitcoin the game is already over. With a second authentication one could be fairly confident that the thief can't send those coins away.

I do agree that this takes away the convenience more than it's actually worth if you just carry small change in your mobile Bitcoin wallet. At least the option of extra security on the user side would help if I want to carry more than what I need for small transfers.

For me the most convenient way would be that it allows a total sent BTC amount during a 24 hour period without authentication. Then if I want to send more than that it would ask for authentication. This is probably a lot of work on the software side but it would be convenient when needed and secure when needed.

I don't actually know how this could be accomplished technically. It would require encrypting the private key for sure so the thief can't access the key once the phone is stolen.

Jan,

but couldn't a hacker, once he has control of your server, upload your private key when you make a connection?

No, and that is the beauty of it.
The server is totally independent of the Android app. To make a release of the app two independent individuals need to take action. Miracle (a company in Denmark) needs to sign the binary with a key that I have no access to. Then i have to upload the signed app to the android market, which only I can do (right now we are actially on two different continents). Furthermore, the app is not updated automatically on your device, you as a user decide whether you want to update, and your device will refuse to update if the signature is not done with the Miracle key.

When sending coins the app asks the server to stitch together an unsigned transaction. Once the app gets the transaction it validates the amount sent and the address of the receiver. Then it signs and returns the transaction, and the server propages it to the network.

Hi, I have an unconfirmed tx in bitcoin spinner... it hasn't sent my bitcoins to the address and isn't appearing in the block chain :S

You can check all pending/unconfirmed bitcoin transactions at bitcoincharts.com (http://www.bitcoincharts.com/bitcoin/). Search for your address there and make sure the transaction was sent. If it's neither there nor in the blockchain, then there may be a problem.

I can't find it anywhere.

I have uninstalled bitcoin spinner and restored my wallet using the QR code backup and now the client says balance "unknown" and coins on their way to you "unknown" :(

That's sounds pretty odd.

Well, if you're willing to post enough personal info about the transaction (or send it to Jan) your coins can be tracked, which will provide clues as to what happened. Not that that would recover your coins if they were sent to the wrong address....

At the very least, the address the coins were sent from, and where they were sent to, would probably be needed.

Alternatively, have you tried copying the private key and importing it into another client?

I tried importing the private key (the spinner backup QR code) to my BlockChain wallet but got an error message :(

Just to be sure, you used BitcoinSpinner's "Advanced" settings option and used "Export Private Key," right? That's not the same code as the wallet backup.

I wasn't, but I just tried that and got an error message too : " Error importing private key: Unknown Key Format " tried importing to strongcoin and got a similar message : " Error: Not a valid Private Key "

Hmm. Well, I'm stumped. Sounds like the latest update may have a bug or two, in which case you should probably wait on Jan. He might want your phone model, OS version, and version of BitcoinSpinner too for good measure.

Last attempt: try going to Blockexplorer and looking for your first BitcoinSpinner address, and see what happened to your coins after they were initially sent to the address. If they didn't move from that address at all, it sounds like they may be lost for good. OTOH, maybe, just maybe the address produced was invalid, and the original coins never left your desktop client (if Blockexplorer reports your address as never having been seen, that's a good sign.)

The server had some problems as it is low on memory. Everything is working now, but I'll have to increase memory soon.

I have been using bitcoin spinner for a while, there is no problem with the address, the bitcoins are still there and havent moved. Hopefully it's my phone that is messing around. I'll wait for Jan to get back to me (i've emailed him). Cheers for your help so far :)

Just as you wrote this my spinner started to spin, and it now works :D cheers Jan!

Jan, are BitcoinSpinner private keys still in SIPA format?  It seemed odd that neither Blockchain nor Strongcoin recognized it.

Yes, SIPA is the format. However you cannot use the backup QR code when importing. You have to use the one from Settings-> Advanced -> Export.
I am travelling right now, so I have to keep this brief.

I tried doing that and it didn't work. I'll try again and report back.

BitcoinSpinner server side is currently down while I increase the memory of the server.

Done

thank you jan!

...and please don't get hacked in the next time....
it seems to a virus or something like this travels around

 :D

Jan, its really important you get Spinner passworded.  its necessary in general and also would give you a leg up on Bitcoin Wallet.

Yes, you are right. It is on my list.

We need to talk ;)

wow!

bitcoin spinner can be sold ?

 :o

I am not sure I follow...

The beauty of this split wallet method is that even if the main BitcoinSpinner server is successfully hacked, this does not expose the users to theft.  This is what makes BitcoinSpinner different and why I use it so much these days.  Well done, Jan; well done, indeed.

Another great thing about Bitcoin Spinner is that its the only wallet app, that runs on older versions of Android. It runs perfectly on my Android 2.1

Thanks for a great piece of software Jan!

Yeah, I really like this app. Its quick and efficient, many thanks.

I think he was implying we're buying you out somehow, which is still sorta technically possible but pointless.

Soon enough we can announce what is actually happening :)

Isn't it obvious?
Bitinstant integration with Bitcoinspinner; go to Wallmart, deposit cash, see the bitcoins appear in Bitcoinspinner.
That's what I would go for anyway :)

Perhaps also the other way around, even, although I don't know what that would require technically. But I read you were working on it ;)

i just joined and this looks really nice. I'm going to try it =)

I've just installed this today on my old phone. It works in Android 2.1!

Now let's go local bitcoin traders!

Not really sure if this has been addresses but forum search didn't find anything (as it is usual) and I didn't read through all the posts. My preempted apologies if I'm dupping here.

Using p2pool I tried using a spinner address for the miner, which obviously works fine just like with any other valid address except BitcoinSpinner doesn't see the mined funds at all. First I thought it was the 120 block confirmation but now I it has been long confirmed and is still missing from the device. The funds are there, importing the address to a fat client sees the funds just fine.

Bug, RFE?

Thanks

The server side is based on BitcoinJ, which currently does not support coinbase transactions (the ones that generate newly minted coins). However, Jim Burton is working on that for MultiBit, and in the process of merging it into the main branch of BitcoinJ, where I guess it will be available in version 0.6. It will take some time before it is available in BitcoinSpinner, but it will eventually be supported. Thanks for bringing this up and good that you could export the private key to a fat client.

Thank you. I thought it could be something server side but was really hoping it was just the client not requesting all it needed... client side is always faster to resolve, if only because the test cases are much more limited.

I'll wait it up, it's not something I need just something I decided to try out.

the search box is broken most of the time and doesn't find anything.

try clicking "search" menu item and search from there. that usually works for me.

The thing to remember is that the search box works differently depending on where you are. If you search while you have a thread open, it only searches within that thread. I think the same applies to when you only search within a specific section instead of the whole forum. It still could use a lot of improvement though.

I have a minor bug when I run the app on my Matsunichi (Le Pan) TC970 tablet.  When I open it, I get a mostly blank (black) screen with just the BitcoinSpinner title bar at the top.  When I press the Back button, the main screen then appears.  Edit: this behaviour only occurs when switching to the app when it's running in the background, not when first launching.

Also, not a bug but a nice-to-have feature is landscape mode for tablets.  It's a nice app all around though, and I'm going to start using it instead of Andreas' Bitcoin Wallet app as the latter keeps locking up on me during blockchain downloads.

There are basically two ways you can do backup/restore

1. Take a picture of the backup QR-code with a secondary camera and print it on paper.
2. Copy the text value of the QR-code to the clipboard, and use an external tool to generate a QR-code from it.

When doing a restore, just scan the QR-code.

I have always used option 1. Copying it to the clipboard makes it available to other apps on the same device.

I agree that this could be somewhat easier, and I have been considering to add the option of writing the QR-code as an image onto the SD card of the device. However, so far I have avoided this as it would require BitcoinSpinner to have privileges to write onto the SD card. I am very focused on limiting the required privileges to the bare minimum, right now BitcoinSpinner only requires:

• Network Communication
• View Network State

This makes it easier for me when I have to defend BitcoinSpinner from paranoid users claiming that it steals contacts or tampers with your SD card etc.

I am open to suggestions.


 

There is an update of bitcoinspinner in the android market today. Amongst the new feature, there's this one: "Buy bitcoin (using bitinstant)".

How awesome is that!

When restoring from backup, why not just have a text field as well and accept the same text that was generated when backing up?

Very, we hope - but watch this space for the official announcement

As some of you have already noticed in this thread BitcoinSpinner now integrates with BitInstant.
Please make sure to read the announcement here: https://bitcointalk.org/index.php?topic=87852.msg965850#msg965850

I pushed the software update to the Android Market before the announcement to have it ready, and some of my dear users found it before the official announcement  ;D

Now it is time for me to focus on some of your feature requests, and adding PIN protection to BitcoinSpinner is on the top of my list. Please have in mind that I am not making a living off this, so please have a little patience. 

I hope they give you a  cut of any income the app generates.  :)

ok, sorry for spreading fud as this is most likely a bug in my android phone and persists for many other sites since at least 6 months:
bitinstant as some other bitcoin related websites show an illegal certificate warning on my motorola defy.
as bitinstant is affected at least on my device, they might be interested in resolving the source of this scary warning.


my phone is rooted, just in case that helps. the problem was there before rooting it.

This is a known issue and is caused by the CA not being included in android. To fix it we will be switching to another CA, but for now please disregard the warning - despite the CA not being in android your data is still secure.

You have a link? Why is this CA not included? In Opera it works.

It probably depends on which Android version you use. If the root certification authority (CA) certificate did not exist or was not included in the Android version your device has, then you will get a certificate warning. The fix is either to upgrade your device or to let the service use a certificate that was issued by an old (established) CA such as Verisign. They charge you big time for this and they make a ton of money.

The phone is rooted so I should be able to import those certificates but I posted here to raise awareness as I don't know how many are affected. It scares people out of using bitcoin when they apparently have some IP poisoning going on on their device (or whatever their guess is).

Server down for scheduled maintenance Sunday July 1 8 PM PST. Maintenance window expected to be 3 hours.
In that window you will not be able to use BitcoinSpinner for transactions. Note that with BitcoinSpinner you can always export your Bitcoin private key regardless of server availability.

I made a backup of the private key and it's been given in the format:


But this fails when trying to import into online wallets like at Blockchain:

Can it be reformatted to work?

Thanks. I used the backup to restore into Bitcoinspinner and it seemed to work even though I have no WiFi or 3G connectivity.
So then I exported the key to the clipboard and wrote that directly into a txt file.
I then copied that into the blockchain.info wallet but I get "Unknown key format".

I'm using v0.6.0b but I can't upgrade it as I'm heavily firewalled.

As far as I remember you have to choose Sipa format when importing into blockchain.info.

Quick and easy question to save me some time trying..

Bitaddress.org can make an addy and a private key.. 

How would I go about making a wallet from bitaddress.org and importing it into spinner ?

obviously I have some ideas on this.. but would like to know the surefire way..

Thanks

Short answer:

You can't. BitcoinSpinner's "wallet" isn't designed that way. The one key it gives is all you can have.

Hmmmm..

So when I uninstall the program, and get a new wallet..  its not a new wallet ?

Because I've been doing this by restoring through QR code I've printed out..

Please explain further..

I am on the move, so short answer. When you uninstall/install you get a brand new wallet. More details here:
https://bitcointalk.org/index.php?topic=53353.msg1024102#msg1024102

As far as I remember you have to choose Sipa format when importing into blockchain.info.
[/quote]


At MyWallet, no option to select as SIPA or base58. But both base58 and SIPA are listed on the features list. So I guess I need to convert base58 to SIPA.

This seems relevent:
https://bitcointalk.org/index.php?topic=3638.0;all

But perhaps I should craft a wallet backup file:
https://blockchain.info/wallet/wallet-format

No rush Jan for help. I'll have to look into this more at a later date. It sounds more like a MyWallet side thing. I have to say, it's not the first time a change in Bitcoin format has caught me out, which is a bit worrying for longevity. It's a good learning experience though. The guy I'm to pay seems very friendly and so forth so that's fine.

BitcoinSpiner has just been updated to version 0.7.0b. You can find the latest version on  Google Play (https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner&hl=en) or as a direct download (http://code.google.com/p/bitcoinspinner/downloads/detail?name=BitcoinSpinner.0.7.0b.apk) for Kindle users.

New Features:

• Added the long awaited PIN protection.
• Added Czech & Russian translation (Kudos to Slush)
• Added the current MtGox BTC exchange rate for the chosen currency to the title bar
• Now displaying BTC balances with full 8 digit precision (before it was with 5 digits)
• Extended Finish translation

The PIN protection feature allows you to set a 6 digit PIN which must be entered whenever:

• Sending bitcoins
• Backing up your wallet
• Exporting your private key
• Modifying your PIN

It is NOT used for encrypting the seed from which your private keys are generated. For that purpose a 6 digit PIN is useless. The PIN is there to protect your from someone who picks up your device and sends your funds elsewhere without you noticing.

The PIN protection feature is optional, but encouraged.
Note: Before PIN protecting your wallet you should make a backup of your wallet (In fact you should always do that). If you ever forget your PIN, you can uninstall and re-install BitcoinSpinner and restore your backup.

Enjoy

maybe a dumb quesiton:

with very expensive bcrypt hashing with added salts, could a 6 digit pin maybe provide reasonable protection against bruteforcing?
so it would maybe take 5 seconds on a phone to calculate the correct decryption key, which is thrown away as soon as the app is closed.

I don't think so, by being 6-digit numeric password there are few combinations to try. I guess it could be bruteforced in two months max.

At MyWallet, no option to select as SIPA or base58. But both base58 and SIPA are listed on the features list. So I guess I need to convert base58 to SIPA.

This seems relevent:
https://bitcointalk.org/index.php?topic=3638.0;all

But perhaps I should craft a wallet backup file:
https://blockchain.info/wallet/wallet-format

No rush Jan for help. I'll have to look into this more at a later date. It sounds more like a MyWallet side thing. I have to say, it's not the first time a change in Bitcoin format has caught me out, which is a bit worrying for longevity. It's a good learning experience though. The guy I'm to pay seems very friendly and so forth so that's fine.
[/quote]

Still can't figure this out...
 anyone else care to try it? (export a private key and import into blockchain.info)

I had the same question.. But everyone seemed to misunderstand what I was asking..


I would like to use my own wallet and private keys in B spinner..

Or be able to use the backup spinner provides anywhere else.. 

And how..  :)

one could bruteforce that with 1.000.000 phones in 5 seconds

Define reasonable.  What is reasonable security for one person with enough bitcoin on his phone to pay for a night on the town is going to be different than reasonable security for a cash mule trying to stay alive and deliver goods to the Zeta's.

I think we need to talk about our target audience.

Which is what?

Crypto-nerds?.

Personally I think that the program should be left this way, or just with encryption that protects you for like 3 days bruteforcing with several GPUs. (I think) You shouldn't break the balance between practicality and security, specially if it's a mobile system that nobody should use with 10k USD. Weak encryption is practical(using thousands of PBKDF2 rounds), specially if someone steals your device, you can get to your home and sweep your addresses easily.

When it comes to crypto stuff there are no dumb questions.

The technique you refer to is often called key stretching, and I would not use it in this scenario.
1. Android processor speed is varying a lot from device to device. What takes 5 seconds on one device takes 30 seconds on another and 1 second on a third. Personally I would be annoyed if I had to wait 30 seconds to send a small transaction.
2. What takes 5 seconds on some Android my desktop computer could do in a fraction of a second. Making brute force attacks very plausible.

In the end doing this would give an annoying user experience and a false sense of security (some would call it kindergarten cryptography).

The key format used by BitcoinSpinner when you go to Settings -> Advanced -> Export private key is the Sipa format. As far as I remember Blockchain.info used to support this format, but it seems not to support it anymore. I have PM'ed Puik on this, and asked whether he will support it.

Just installed bitcoin spinner after doing some research as to which android wallet to chose. So far I'm rather impressed.

I got some 'illegal operation' message, and I didn't understand why. So I tried to quit the app, but didn't see an exit option ? Not even when clicking menu, so I rebooted the phone, and when I started bitcoin spinner again, the same error was present.

Then I checked the bitcoin address, and it seems I had pasted an extra space at the end. Perhaps it would be a good idea to trim spaces automatically ? I copied mine from an sms message, and the extra space seemed to be added automatically.

Also, perhaps there would be some very easy method of adding addresses ? As it is noe, I first typed in an a entire bitcoin address for hans, which is fine because I'm a computer geek, but would still like to have it easier, so what about some feature where you can insert an address to the bitcoin spinner website, get a short code (4 alphanumeric) in return, and you could then import this on the phone by entering that code (app would connect to server and get the address). Or there could be a registration system that could sync bitcoin addresses betwen an online wallet and the bitcoin spinner.

I like the transaction history, and overall I think the app is well made. Great that you keep the infrastructure ready for this. Perhaps it would be possible to offer premium editions with some of the features I listed above ? Will throw some coin your way if this works as good over some time as it is working currently. Impressed. I also saw the ratings on Google Play (what an odd name!), and almost all were very positive, so this was absolutely some great work!

Version 0.7.1b is out. Find it on Google Play (https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner) or on the BitcoinSpinner project page (http://code.google.com/p/bitcoinspinner/downloads/detail?name=BitcoinSpinner.0.7.1b.apk) for Kindle and other devices that do not use Google Play.

The only change from 0.7.0b to 0.7.1b is a private key export bug fix:
It turns out that BitcoinSpinner had a bug where the exported private key some times (more often that not) is formatted for testnet instead of prodnet.
More details here: https://bitcointalk.org/index.php?topic=53353.msg1078070#msg1078070

Thanks!

What did you do to get the 'illegal operation'? Many android devices allow you to send an error report if this happens. If you do I get a stack-dump that tells me exactly where it happened, which is very useful for debugging.

This must be when sending coins? I have added some trimming to avoid this. This will be included in the next release.


Bitcoin addresses are not very handy, and easy to get wrong. I think that this is why more and more Bitcoin sites allow you to just scan a QR code, which is by far the easiest way to get the address into your device.
There are two very easy ways of adding addresses to your address book with BitcoinSpinner:
1. Scan a QR code containing a Bitcoin address - More and more web-sites display QR codes, and if you have an address as a string you can for instance paste it in the Search field on Blockchain.info and it will display the QR code for you.
2. Add an address from 'recent receivers' - If you have sent some coins to an address this feature allows you to select the transaction and add the receivers address to your address book.

Other wallets ask you whether you would like to add the receiver to your address book whenever you do a transaction. This really annoys me as most of the time I don't want to do this as I send to one-time addresses, like when doing a purchase. This is why I made option 2 above instead.


Great, and thanks.
BTW, there is a 'Donate' option you can access if you click the option button on your phone on the main screen of BitcoinSpinner. It hasn't been tested much  ::)

Thanks for the reply. What about increasing the fee a tad and make some of it go towards your reward ?

There could still be the option for the cheapskates to compile it themselves and remove that extra fee.

Not sure how the user base would respond to that. Your time and resources ain't free, so..

Depends on the amount.

If the mandatory 0.0005 BTC fee was increased to 0.001 BTC, with half going to donations and half as a transaction fee, I doubt anyone would even notice. For that matter, I'd recommend at least a 0.0015 BTC fee, with 0.001 BTC being for donations. With current BTC prices of ~$10, that's less than 2 cents total per transaction. Extremely reasonable.

But anything more than 0.005 BTC total, it might limit my use. Anything more than 0.01 BTC would have me reconsider using BitcoinSpinner.

As much as I believe he deserves some acknowledgement for this cool app I'm pretty sure all that did great stuff like this will get their fair share when the big players search for people to get them started in bitcoin.

Rolling my own spinner is high on my todo list and probably I would put it to the market under my account for my friends that might trust me more than some guy they don't know/takes money with every transaction.

I have a cool non-bitcoin app, too and really would love to make it open source but to be honest I don't see how to make money with it. One approach I was thinking about was to make the core app open source and the shiny frontend only wraps this. I would have to provide a non-shiny front-end to provide a full app others would consider worth working with, so my base framework would be there to establish a standard within this area and my nice front-end would stand out and be worth paying for.

Similarly would I not be mad if further development on the spinner-UI would be non-open-source and only available for a fee but I would find it sad if bug-fixes to the core functionality would not find its way into a lib-spinner.

Will there ever be a way to redeem a private key (e.g., scan a QR and redeem?)

https://i.imgur.com/RyG2L.jpg

Because Bitcoin Spinner uses deterministic keys, it couldn't store the private keys that are scanned.  But what it could do is create the transaction that spends the private key scanned to a new bitcoin address in the Bitcoin Spinner wallet.

This will allow Bitcoin Spinner to remain the only Bitcoin app I need on my mobile.

To do this the BitcoinSpinner server back-end has to be able to determine the unspent outputs of the private key in real-time. Today it can't.
This would be an awesome feature, and my plans are actually to do something that is even more interesting. However I am sorry that I cannot reveal more details on this for the next month or two.

Fyi...

I took a peak at a back up qr..

I formatted my own personal key into the QR code..

restored the wallet..


It made a wallet, but does not have the money I had sent into it..  therefore it must be a new/diff wallet..

I grabbed a key from Vanitygen..   of course.. this is a vanity address and priv key I want to import..


I have no idea what "type" of priv key vanity spits out..


Im actually suprised it did anything let alone make a wallet that is not the intended one I want to use, mind you I never tested its functionality, I would just assume it works..   but.. not how I wanted it to...

Any tips ? 

I've been using spinner happily for a month. One detail bugs me: descriptions on Google Play and the wiki repeatedly refer to "private keys" in plural. And yet, from what I see there is only one private key involved, and its corresponding address. The only way to obtain a new key is to erase app data folder, so the new key pair is generated on the next start.

Am I missing something here?

Not really, the client only uses one key at the moment but is more than capable of handling more.  The one key rule has more to do with conserving bitcoin spinner's server resources.

The backup QR code contains a random 256-bit seed, not a private key. From that random seed the bitcoin 2 private keys are deterministically generated. The first key is your login key, the second one is your bitcoin private key. Gory details here: http://code.google.com/p/bccapi/source/browse/trunk/src/com/bccapi/api/BitcoinClientAPI.java
If you use a bitcoin private key as the seed it will just be treated as a 256-bit random seed from which there will be generated keys which ties up to the next question:

The BCCAPI (http://code.google.com/p/bccapi/), which BitcoinSpinner is built on top of, allows you to manage a number of Bitcoin addresses. However, the main drivers for BitcoinSpinner are security and simplicity. And managing just one Bitcoin address/private key does make the UI much simpler to use. Now, as noted above there are two private keys in play, but the other one is used for login purposes.

This being said, there is a trick you can do to manage more than one address.
1. Install BS, which automatically generates a new random account and bitcoin private key
2. Make a backup, and print it on paper
3. Uninstall BS
4. Install BS, which automatically generates a new random account and bitcoin private key
5. Make a second backup, and print it on paper.

Now you have two different wallets, and you can switch between them by restoring from your two paper backups. Whenever you do a restore the previous keys are wiped from your device, making this a very useful feature for cold storage. I do this myself for the bulk of my coins.

Yes, this could (should) be built more seamlessly into the app.

Yes, also that.

Great, thanks. I am happy the way it is now, I was just confused with the description talking about "keys" in plural, and wanted to make sure I wasn't missing anything.

I'm getting 'an unexpected error occurred' right after it says 'please wait while the network fee is being calculated' when I try to send bitcoins at the moment. Not sure why this is.

Additionally, there have been several times when I've sent or received bitcoins to a bitcoinspinner recipient of vice-versa and it's taken a half hour before it shows that the coins are on their way.

The first issue is obviously higher priority, but any feedback on either would be appreciated.

Thanks,

-bgc

It seems that the 'unexpected error' was caused because apparently the transmission fee is no longer a fixed 0.0005 but is instead calculated, and I didn't have enough in my wallet for the amount I wanted to send + the calculated TX fee. The send worked after I tried smaller values, but the TX fee was 0.01 (although, if the TX fee causes a faster transaction I guess I can't complain... would like to be able to customize it though.

1bitcent? What the hack? How can that be? In Spinner you should not be able to have huge transactions. anything beyond 0.001 should be a bug, shouldn't it?

I misremembered. I checked the transaction and it was a 0.001 fee, not a 0.01.

Sorry for the confusion.

BitcoinSpinner dynamically calculates the fee necessary to guarantee that your transaction gets propagated through the network. The formula is based on the size of your transaction, and basically is 0.0005 * min (1, transaction size in bytes / 1000). If your wallet consists of many small input transactions the transactions you send will be big. So, instead of paying 0.0005 you will pay 0.001 or maybe even more.
So, why do I enforce this instead of letting the end-user decide whatever fee he wishes to pay?
The answer is simple: The end user needs a nice user experience. If I let the end user send with whatever fee he would like then some users would say "Hey, I don't want to pay any stinking fee, I'll send with a zero fee!". The end result would be users with transactions that never reach a miner, as the intermediate nodes would discard them. The end result would be "Hey, BitcoinSpinner is crap, it doesn't work".

So, why are there fees at all? Fees are there for two purposes:
1. They prevent someone from flooding the network with minuscule transactions. AKA DOS attack.
2. They provide miners a reason for mining once the mining reward diminishes.

The fee calculated by BitcoinSpinner only guarantees that your transaction gets propagated through the Bitcoin network (provided that it consists of nodes of the Satoshi client type) it does not however guarantee that your transaction ever gets into a block, but so far this has not been a problem.

Going forward mining fee calculation may get even more complex, as miners will start looking more closely at the fees, and only select the ones with the highest fees. Currently there is a upper limit on how big a block can be, so once the number of transactions get so high that the block size limit kicks in, then miners will only pick the transactions with highest fee pr byte.

Enough of that. Let's get back to what you experienced. You got an "unexpected error" while sending the last cents from your wallet, and as the fee (0.001) was higher than you expected there were not enough funds to send the transaction. That could clearly be handled better by BitcoinSpinner, and I'll look into that.

Thanks for the error report, and I am glad that you found a workaround.

I'm having a small problem with bitcoinspinner.. I sent some coins to my spinner address a while back yet they never made it out of limbo. Spinner shows them as "coins on their way to you" and has for days.

I checked on blockchain.info and the address does in fact have coins, and the transaction has 500+ confirmations. Any idea what could be the problem?

Please PM me your bitcoin address, and I'll take a look

Um.. did you do.something? It's fixed now.

BitcoinSpiner has just been updated to version 0.7.2b. You can find the latest version on Google Play (https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner&hl=en) or as a direct download (http://code.google.com/p/bitcoinspinner/downloads/detail?name=BitcoinSpinner.0.7.2b.apk) for Kindle users.

New Features:

• You can now restore a backup from the clipboard in addition to using a QR-code. When using this feature the clipboard should contain the same text that you get when clicking 'Copy to clipboard' while the backup QR-code is shown.
• Now displaying a message when your device is unable to connect to the server as opposed to just ghosting buttons on the main screen
• Minor bug fixes related to the address book and some UI tweaks

If you happen to attend Bitcoin2012 (http://bitcoin2012.com) don't miss my presentation on BitcoinSpinner. I'll be doing an interesting announcement about future development :o

Enjoy

Looking forward to your talk.


has to do with bitpay? ;-)

BitcoinSpiner has just been updated to version 0.7.3b. You can find the latest version on Google Play (https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner&hl=en) or as a direct download (http://code.google.com/p/bitcoinspinner/downloads/detail?name=BitcoinSpinner.0.7.3b.apk) for Kindle users.

New Features:

• Support for sending coins to multisig addresses - With this change BitcoinSpinner creates BIP-0013 (https://en.bitcoin.it/wiki/BIP_0013) (aka p2sh) compliant transactions when sending funds to multisig addresses.
• Backup notifications - Making a backup is really important if you don't want to loose your coins. With this change a backup notification is displayed on the main screen whenever the app is restarted and you have a positive balance. The dialog allows you to disable the notification so you don't get nagged if you have made a backup already
• Address book fixes for Android 2.1

Enjoy

Thank you for your effort.
Not high priority, but please reconsider the UI.

Might be nice to have a bit of intelligence on that. Rather than every time, just when first started and when new keys are added.

Making a backup is a one time task. BitcoinSpinner generates its keys from a seed (deterministic), and currently is limited to one bitcoin key-pair. The latter lets BS have a simpler UI.

Hi Mr BitcoinSpinner author, may I make a request?

Can you add more currencies to display the estimated worth of the bitcoins? A website called localbitcoins.com allows you to "convert" to 150+ different currencies, since it uses the rates found on openexchangerates.com.

My country's currency is not in the list, it only has a dozen or so. I understand those have online exchanges that trade in those currencies, but you can estimate all the others by comparing it to the USD, for example.

And can we choose between last price, low price, high price or weighted average? Since you are getting it from Mt. Gox anyway. I personally prefer a weighted average.

Tested: version 0.7.3b is capable of sending funds to multisig address.
An example for a tx is:
http://blockchain.info/tx/368afc1e3be84dd11912c0e90eeacd4395a2d49eddf122d25e3a1aabda5b05f9

Thanks you!

Devcoin Bounty (DVB) Voting! Please Vote
https://bitcointalk.org/index.php?topic=101559.msg1268902#msg1268902

DVB is calling its shareholders for the first voting upon a Bounty.

Bounty Vote:
DVB sponsors 9 000 000 DVC for the development of a GPL DVC Android App similar to BitcoinSpinner.

Plus:
https://bitcointalk.org/index.php?topic=34586.msg1271093#msg1271093

The spinner seems unable to communicate with the server at this moment. It hangs at startup, then "send bitcoins" and "transaction history" buttons are greyed out.

How often has the system been down in recent months? What is the uptime percentage?

Problem persists :(
Sadsadsad. Spinner is my fav. Hope we soon have bloom filtering so we don't depend on a custom server.

I don't have a down-time percentage, but it has been low. There have however been two giltches the last two days. This should be fixed now.

Great, it's back to normal!

BitcoinSpinner v0.8.0b is out. You can download/upgrade it from the Google Android market (god know why, but they call it Google Play these days), or fetch it directly from the project site (http://code.google.com/p/bitcoinspinner/downloads/list). The differences may seem subtle, but it is backed by 1 1/2 months of hard full time work where most of the time has been spent on the backend system.
User visible changes:
 - Even faster: The next generation BCCAPI is simpler, has fewer lines og code, requires fewer server roundtrips during startup, while being as secure as before.
 - In addition to displaying "coins on the way to you" on the main screen it also displays how many coins you are currently sending.
 - Transaction history color coded to make it easier to distinguish receives and sends
 - Transaction history now displays the address you received coins from instead of displaying which address you received the coins with.
 - Better error messages when trying to spend your last coins while you cannot afford the miner fee.

BitcoinSpinner is now backed by another version of the BCCAPI, which makes it much easier to manage multiple redundant servers as they no longer need to share anything but the block chain.  I will maintain backwards compatibility with version 0.7.3b for about a month, leaving people time to upgrade, whereafter I'll scrap the old server. This allows me to manage multiple redundant copies of the new backend, which has been requested by several.
 
Enjoy

Thanks Jan for your great work on my absolute favorite Android Bitcoin Wallet.

BitcoinSpinner v0.8.1b is out:
 - Fixed typo in German translation
 - Fixed a fee validation bug that occurs when sending a transaction with many small inputs. The effect has been observed to prevent you from sending your last funds when you have many small inputs. Thanks to Object 2212 for helping me test and debug it.

It might take an hour before you can update it from the Android Market.

Enjoy, and Happy New Year!

Would like to see that, too. Maybe it is possible to swipe the coins from the scanned key.

i've just sent some coins from one spinner to another one. tells me since hours that "couins on their way to you: ..." but that's it. does this also happen to others or is it just my setup/account here?

Server running low on storage, working on a fix.

Fixed.

Jan, do you make available some compounded statistics?
It would be nice to see the total number of wallets over time, or number of transactions per day.

With the earlier backend implementation I could get precise statistics as it only tracked the transaction inputs/outputs of known BitcoinSpinner wallets. The new implementation, which has been in production for some months now, does not track BitcoinSpinner wallets in particular. It tracks all bitcoin addresses in existence, and does not 'remember' which ones have been queried for unspent outputs, transaction history etc. This allows it to be stateless in the sense that the only information it has is what is readily available in the Bitcoin network, which will allow me to have multiple totally redundant copies.

What I do know is how many active device installs there are according to Google Play. The current number is 2009 which is the number of devices where it was installed and not uninstalled. This number does not cover people who installed it from other sources.

great, thx. I can confirm that my 10+ btc show up as they should :-)

TLDR: I want a dedicated secure Bitcoin Wallet with open source that I compiled myself.



The rest is kind of brain storming. I warned you:
As Bitcoins become more valuable, I spend more time on how to get them secured. BS looks like an amount of code I can review. bccapi maybe not but I assume, others do that. Generally it would be cool to have some project that collects signatures from people that did actually review code as I'm pretty sure it would be rather easy to abuse the users trust.

Anyway, I just bought the cheapest tablet I could get to run it as a dedicated bitcoin wallet with is either Schildbach or Spinner. Plan was to not install anything remotely related to bitcoin except for a wallet I compiled myself.

Schildbach and BS have the private key plain text on the device which is kind of unsafe.

I know that protecting against some unspecific attacks of "free chargers" copying all files from my device are maybe not really the main threat but still I guess this should be taken care of.

I just got started digging into the code and wonder if there would be an "easy" way to lock it down some more. My idea was to stick with the n digit password but to actually use it (For non-devs: Now it is only an interface-gimmick preventing friends from silently toying around with your money but don't protect you from malicious USB chargers or a phone-thief moving your money within minutes). You could for example determine the speed of the device and hash x times the 6-digit password to generate a decryption key with x roughly taking 10s on the device. For this to be still fun, you should only use the priv key when sending bitcoins (like bitcoin-qt but delayed 10s for hashing). An attacker that somehow just got the encrypted priv key and the plain text "SHA256 applied 12,184,276 times" would take significantly longer to actually get hold of the bitcoins than now. Also allowing longer passwords would then make sense. (some "the average Joe's bot net is 15,000,000 times faster than your phone and would brute force your password in 17.3h. Never put more money into your wallet than bot nets cost to run for that amount of time" might be miss-leading as other attacks might be cheaper.)

Sure, such hashing would also allow to safely use shorter passwords in bitcoin-qt but there a longer password is not such a pain to enter … maybe?

---

Pro-Tip for Android rooters: On a rooted Android with "USB debugging on", Spinner's and Schildbach's wallets are open books to any PC you charge your phone at.

Ahhh! is this the right thread? Maybe lock and use only this (https://bitcointalk.org/index.php?topic=53353.0)?

Thank you for your suggestions.
You are absolutely right regarding the current PIN security. It is there to avoid someone from grabbing your phone and move your coins while you look the other way.

I have been thinking along the same lines regarding encrypting keys, and didn't do it for the following reasons:
 - Entering (secure) PIN/passwords on a smartphone is a real pain as it has to be long/complex
 - Doing "key-stretching" on a shorter/less complex PIN (for instance hash the PIN many many times) takes long time if you want it to be secure. Using a fixed time (say 10 seconds) is not equally secure on every device as they have different CPU power and all have to compete with for instance a fast desktop computer, or maybe even an Avalon

Instead I do something else. I have two paper backups: one for my savings, and one for my daily use.

Normally I only have the wallet for daily use on my phone. Whenever I need to recharge it I:
1) Restore the savings wallet on my phone (Click the options button->Settings-> Restore wallet and scan the QR-code for your savings wallet backup)
2) Send funds to my spending wallet (I have the address in the address book, so it is really easy)
3) Restore the spending wallet (Click the options button->Settings-> Restore wallet and scan the QR-code for your spending wallet backup)
The entire process takes less than a minute

The important thing is that after step 3 the private key for the savings wallet gas been deleted from my device.

You can make this even more secure if you (as you suggest) use a dedicated device with nothing else installed.

Thanx for the explanation. Now I only need some non public printer without hard drive to print some qr codes.

I have one. Email them to me and I'll print them for you. :)

Why the testnet version isn't working?
"server not responding"

The testnet server was used during initial development. It hasn't been running for a long time to reduce cost.

Ah, thanks.
So I can uninstall the app, now.

I've been using BitcoinSpinner for a while now and like it quite a bit. I think I've read through most of this thread, so I apologize if I missed the answer to this: What happens if the backend server goes away? Can I still retrieve my coins somehow?

If the answer is no, then the one feature I'd like to request is the ability to change the backend server that the app connects to (and if a special backend server is needed, can that software be open sourced?). In the event that you and/or your server go away, I would hate to loose access to whatever coins I have stored in my wallet. Would something like that even be possible?

Besides "backup wallet" option, there is the "export private key" under "advanced" settings. I have not tested the functionality myself, but if this is the actual private key, we should be able to import it into any client.

Niko is right. The ability to export your private key has been there from the first release. For one of my spending wallet I have exported the private key and imported it in a blockchain.info wallet. This way I can access the same funds from my BitcoinSpinner Android phone and blockchain.info iPhone app.

So now that you read this thread, join us on the other thread (https://bitcointalk.org/index.php?topic=53353.0). Yes, I suggested to lock either but they are both live.

Hi everyone,

I've just seen that on FDroid since 01.05.13 there is a new version of BitcoinSpinner 0.8.2b. At the moment I'm using 0.7.3b as this was the latest version on FDroid. FDroid tells me that version 0.8.2b is signed with another key than 0.7.3b.
Is this to be expected?

I have mot compiled or signed the FDriod distribution and cannot vouche for it. However I have been in contact with a developer at FDroid on some build related questions, and I have no reason to believe that their distribution is evil.

If the FDriod distribution is signed with a different key than their previous version you can only upgrade by uninstalling and reinstalling. Keep in mind that you MUST make a backup before uninstalling (You should always do that anyway)

The distribution found here (https://code.google.com/p/bccapi/downloads/list) and on the Google market place (https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner) are the officially signed ones using the same key since the initial release and allow you to seamlessly upgrade. Those I can vouche for.

Any chance of porting this over to blackberry 10? 

I don't have a blackberry and frankly don't have the time to do it. The sources are open and if you know a skilled blackberry developer up for it I'd be happy to give him my support.

Thx for the quick info!

Could someone give me some tips on importing this into Eclipse? I checked out from the repository OK, created a new workspace but when I try and import the project, either using "Existing Projects into Workspace" or "Existing Android Code Into Workspace", I get errors both ways.

Nevermind, I think I got it figured out. Just some generic windows weirdness and then problems because the .classpath file was hidden (i.e. more windows weirdness).

Still not having luck. It seems to start with


Search turned up a few suggestions but none of them helped. I'm sure it's something simple though. A little help?

I use MOTODEV Studio with Android 2.1 SDK installed
I have checked out the code in .../source and have .../source/BitcoinSpinner, .../source/bccapi, .../source/bitlib

1) Create new workspace
2) File -> Import -> General -> Existing Projects into workspace -> Select root directory: .../source -> Finish (three projects selected)
3) In package explorer find: BitcoinSpinner -> src -> miracleas.bitcoin_spinner -> Main.java -> Right click -> Run As -> Android Application

You probably want to run it on a real device instead of an emulator, as it is faster and lets you use the camera for scanning barcodes.

Hmm. Not sure why it is not working in Eclipse then. It was pretty much the same process.

Not too worried about the scanning for my purposes so the emulator is fine from that point-of-view. This appears to be some weird link-type error though. I'll have to look in the apk and see if the classes are present. I don't see any reason they wouldn't be though.

Yep, no classes in the APK. That'll do it. Have to figure out what the deal is there.

Nevermind, looks like they're in the classes.dex probably. So still head-scratching.

I managed to get it going by deleting the bccapi and bitthing folders from the workspace and copying the source files directly into the bitcoinspinner source folder. Obviously not optimal but it will do for now :D. The only other thing was that some of the calls involving string and charset were apparently incompatible with the API level (something to do with needing api level 9). Setting the min and target sdk levels fixed that though and it's up and running. Now to mine some coins into that address and try and catch what's going on.

Not sure if this is a bug in bitcoinspinner or just my cobbled-together setup. I mined some coins to the address and they showed up OK but when I click on "View transaction history", I get a null pointer error in AsynchronousApi.java, line 171. I wonder if because there *are* transactions but none of them can be displayed, I get this error. I'll try sending some coins there through regular transactions and see what that does.

s is null from map.get(item.hash);

There are two entries in map.table, 0 and 1 and both are null. I assume that this is related to transactions.array which is in a similar state.

I'll try and work out what's going on as I dig in deeper but I just thought this might be something of interest to you.

Edit: Sending more coins to the wallet did not help with the null pointer. So next up I have created a new wallet which received sent coins OK and next I will try to mine to it.

It's looking to my like BCCAPI isn't returning any info when the info for the mined transactions is being requested. But I'm not sure on that yet. More to discover...

As I have never mined I did not have the opportunity to test BitcoinSpinner with coinbase transactions. My gut feeling is that it chokes because the transaction has no outPoint (funding transaction). Can you send me a stack-trace and a transaction ID?

- Jan

This is a amazing project!

Hi Jan, I posted over in the bccapi thread. It appears that there are a couple of issues at play. Foremost is that bccapi appears to not return information for transactions from mining (Though it does list them in the transaction history object it returns). This puts an immediate stop to any plans I had to add that in (in fact, it seems it's possible that if BCCAPI did return the information, Bitcoinspinner would display them correctly anyway). Secondly, Bitcoinspinner seems to not handle this missing information gracefully. However, this appears to be conditional somehow as I mine to my wallet on my phone all the time and it runs fine (apart from not displaying the mining transactions).

It would be really nice to be able to change the unit to mBTC on BitcoinSpinner. I cant see that option currently.

Small payments are troublesome in BTC. Sometimes I put too many decimal places

Sent a transaction at 8:44. Still listed as incomplete in BticoinSpinner's transaction history but *does not* appear in the blockchain at all.

I missed out on a group buy because of this and now have coins presumably heading somewhere where they will no longer do me any good. Not happy.

http://blockchain.info/address/13qnEgPTxJW6mm88dLpnHXZyryN5EXBciq

http://i41.tinypic.com/aosu1k.jpg

The transaction you sent has the following hash 6b92ba8967f1a8794b30acc30e8dc13848e2cab70cb919d29c15631e184f0f3d and is being rejected by the network.

The problem seems to be that that it uses input 185 from this transaction 5826ac8c46bd42de7d9a80b0168bc022b483b2c14a099f28e1c6ca1adfd4f445 which is a coinbase transaction with 55 confirmations. The network will reject your transaction until the coinbase transaction has matured, which happens after 100 confirmations.
 
The root problem is that BitcoinSpinner does not regard coinbase inputs as unspendable until they have matured. This is clearly a bug, and something I'll have to look into.

After 45 additional blocks your transaction will no longer be rejected, and the next re-broadcast attempt after that will successfully push it into the network.

I am right now working full time on the next generation of BitcoinSpinner, lit will be a full rewrite. Allowing the user to specify mBTC instead of BTC will be included along with an awesome set of new features.

Sorry for not getting back to you on this issue earlier. As I noted above BitcoinSpinner does not handle coinbase maturity. This means that if you mine directly to a BitcoinSpinner wallet and it sends a transaction that references a coinbase input before it has 100 confirmations it will get rejected by the network until the coinbase has fully matured. The effect will be that your transaction will get delayed anywhere between 0-100 blocks.

OK. I'll stop sending my coinbase transactions to bitcoinspinner for now.

Hi Jan, I think this is a separate issue as the transactions I was testing against were most definitely mature. Since I'll be discontinuing mining to the bitcoinspinner wallet, this is not really an issue for me anymore. I did like seeing the transactions come in but I'll probably just put together an android app for that.

Update: I have made a fix on the backend system, and Richy_T has confirmed over PM that he can now monitor his coinbase transactions using BitcoinSpinner. The bug was not directly related to coinbase transactions in general, but to the 'strange' zero value transaction output at the end of each transaction that the mining pool he uses adds. Look for the last output in this sample:  https://blockchain.info/tx/7b5cfb3365f1fe227376b218c0db681fda089d0582190f78d315c3ab019782bb

Interesting. I'll pass this on to the pool guys too. Thanks.

This is awesome news! I am looking forward to it!

Will it be also possible to import private keys from WIF51 format? At the moment it can only import ("restore") from bitcoinspinner's proprietary wallet format.

Reason for my question: I'd like to generate a key with vanity address with "vanitygen" and use that one in my smartphone, like "1phoneXYZ..." to be able to differentiate it from my other addresses.

I love Spinner, but I would love it even more if we could import private keys, I also would love to use vanity addresses on my cell.. :)

That feature is announced for the rewrite.

... and it is soon going into closed beta  ;)

*risehandsforbeta* if it's open source.

So is this, from a Kévin Forest, not an approved release?  (it is named "Bitcoin Spinner"):
 - http://appworld.blackberry.com/webstore/content/20080938/

is there a way to copy the address I just sent money to?

in other words: I would greatly appreciate the transaction history item have a context menu that at least contains: "copy receiving address".

I didn't build or sign the APK, and don't know the developer who did, and thus cannot vouch for it's integrity. If I had a BB I would only use this version for pocketchange.

You will get it all in the next generation wallet.
Andreas and I are making the final touches on the Mycelium wallet. Right now we are at the "getting new server certificates, Google Play publishing certificates, and publishing sources" stage. Just a few days until open beta.

Molecular, I happen to remember that you used an Android 2.1 device. The new wallet will be Android 2.2 and forward only (more than 90% of the market), so I really hope you have upgraded in the meantime.

wishlist:

Be able to
* specify fiat amount for tx.
* swipe private keys.

 ;D

* specify fiat amount for tx.
Yes, both when sending and receiving

* swipe private keys.
Almost. You can import a private key, spend from it, and delete it.

sweet

I like it. Because of the security risk I assume you write a warning or something...

Yes, I now have phone that pretty much dwarfs the desktop I had just 1 year ago.

Apart from the fact that I hate to use it as a telephone (yes, you can use it as a telephone) because of very bad microphone / earspeaker design and that I almost need a backpack to transport it (where are the small phones?!?) and the display breaks easily (just one drop from about 60 cm into the shower tub did the trick), it's a great device.

I also must say again that I like mycelium and it'll probably replace spinner. Love the multi-address feature, however for me to use this safely, I suggest 2 changes:

• before receiving money to an address, display warning if the private key is not known
• when deleting a private key that has money on it, mention that in the delete confimation dialog

And one question: can mycelium combine money from different keys when sending? It currently seems to me that the 2 addresses I have are handled as completely separate wallets? If that's correct, you could call them "wallets" instead of "addresses".

Good ideas, I'l add them to our list

The way the Mycelium wallet works right now is that you work with one key at a time. This means that balance, transaction history, sending/receiving all works on the currently selected key or address. This gives you fine-grained control over your keys, and that has its merits. We have been thinking about changing that to a model where keys/addresses are treated as a pool. This has the following consequences:

• Balance: The combined balance of all your keys and addresses (address = 'read-only wallet')
• Transaction History: The combined history of your keys and addresses
• Sending: Spend from the sum of funds available to your keys, addresses ignored
• Receiving: Your default receiving address will be used. You will select which in the Keys & Addresses view.

While the above is all nice, it also means that you will have less control when accessing your cold-storage (import key / spend / delete key), as the key will be part of the list of other keys and you may do a spend from several addresses. To alleviate that a special single key mode has to be made while not cluttering up the UI.
If more people ask for it we may make the change.

I'll lock this thread to let the discussion continue in the dev thread here: https://bitcointalk.org/index.php?topic=53353
We are busy discussing the Mycelium Bitcoin Wallet over there... the successor of BitcoinSpinner, come join us.