Bitcoin Forum

Hi All,

Last night a buddy who works at Google and I released Bitcoin Android.  It's an open source app for sending bitcoins from your android phone.

https://github.com/barmstrong/bitcoin-android/raw/master/screenshots/btc1.png

https://github.com/barmstrong/bitcoin-android/raw/master/screenshots/btc2.png

https://github.com/barmstrong/bitcoin-android/raw/master/screenshots/btc3.png

https://github.com/barmstrong/bitcoin-android/raw/master/screenshots/btc4.png

Here is a link to the Android Market page:
https://market.android.com/details?id=com.bitcoinandroid&feature=search_result

The GitHub project page:
https://github.com/barmstrong/bitcoin-android

And a YouTube demo video:
http://www.youtube.com/watch?v=W6EucS5RS24

Some features of the app:
* Send and Receive bitcoins entirely from your phone (no server component required)
* Scan and generate QR codes to share address, amount, etc between devices
* Recognizes the Bitcoin URI format
* Creates transactions in the absence of internet (will retry when you reconnect)
* Email invoices from your phone to request money
* Wallet file backed up in the cloud (synced to your Google account) in case you lose your phone.
* A free app, 100% open source

The app is based on the BitcoinJ library that Mike Hearn at Google wrote.  We'd love for you to try out the app it out and send us any feedback!

As you can tell we created a new account on the forum to post this and it looks like the new rules prevent posting anywhere but here!  We'd really appreciate it if one of the more experienced members could post a note in this thread linking people over to this new thread:
http://forum.bitcoin.org/index.php?topic=1812.120

Or if there is a way to promote this thread out of newbies or give us the ability to post elsewhere that would be excellent!

You can try out the app here by clicking "Install" and sending it to your phone: https://market.android.com/details?id=com.bitcoinandroid&feature=search_result

Thanks!

Oh sweet...I wish that had that for iphone. We only have like stock market type apps.

Q: Does It have to download all the blocks when you first start using it or are you accelerating this process somehow?

BitCoinJ offers the option to store only chain headers, which are relevant to your wallet. Highly unlikely they didin't used it.

Awesome!

Mine took about 14 hours to download the 13MB ish block chain headers it needed.

I don't know what was causing the slowness; perhaps some sort of flooding protection from the nodes being downloaded from.

Anyway; it finished in the end.  I'll try a few little transfers today, and see what happens.

Update:  I just noticed the "wallet is saved to the cloud" item.  Not sure I'm happy about that.  Storing wallets in the cloud unencrypted is asking for trouble.  I might trust google with my email; but I'm not sure I'd trust every google employee past, present and future not to download every wallet.dat in the cloud and then just wait ten years.

If I'm storing a wallet in the cloud; why don't I just use an ewallet web service?

You are correct.  Two things helped optimize it:

1. BitcoinJ only uses headers so the entire production blockchain is about 14MB.  We keep this on the SD card.  Many phones have 8GB SD cards so 14MB is not too bad.  (The wallet is stored on the phones internal memory and is tiny in comparison).

2. We include a recent blockchain with the app when you install it, so the first time you run it, it only needs to catch up the last bit.  It's recommended that when you install the app to run it the first time over WiFi.

In our tests, the first launch of the app updated the blockchain in about a minute over WiFi.  After that, updates were near instantaneous over 3G or WiFi.

Of course, it is beta software so there may be differences amongst devices, etc.  A few more details can be found here: https://github.com/barmstrong/bitcoin-android/wiki/Technical-Details

This is the killer app.

Is the wallet safe? Where is it stored? Encrypted, not encrypted?

Not sure what might have caused the slowness.  Sorry about that.  In our tests the first blockchain update finishes in a couples minute over WiFi (with the cached copy included in the app).  After that, updates should be near instantaneous (a few seconds) over 3G or Wifi.

It's def recommended to install the app and run it for the first time over WiFi.

On the encryption, we agree and will probably make the backup to the cloud optional soon, and encrypted for those who want to keep it.  For now we just wanted to release it to start having people test it.  I wouldn't suggest keeping real amounts of money on there at this point anyway (it's still in beta).  You're more likely to lose your coins from a software crash at this point.

Regarding ewallet providers (and server-client mobile apps), there isn't one we trust right now, so keeping it all on your device (and ideally encrypting the wallet for backups) seemed better.  If there was a trusted ewallet provider, I think would be better long term though.  Thanks for trying it out, we appreciate it!

Thanks!  There are some more details here (esp under Technical Details).  https://github.com/barmstrong/bitcoin-android

Zero encryption on the wallet file at present, so use with caution (it's still in beta and I'd expect this to change soon).  Hope it helps!

Absolutely awesome.

Must... buy... Android phone...

I only run on wifi; so speed of connection wasn't the problem.

I'm not sure cached copy was installed correctly.  I watched the file stored in /sdcard/Android/data/com.bitcoinandroid/files grow from 0 to 13.95M very very slowly.


I'm not sure you've really understood the ramifications of storing a wallet in the cloud.

The wallet doesn't have coins in; it has keys in.  Therefore it doesn't matter how many coins are in that wallet when it is uploaded; it matters how many might be in it in the future.  It doesn't matter that it will be encrypted in the future, it matters that it's not encrypted now.

Anyone who steals a copy of your wallet today can watch and wait for the rest of time until you put something in it worth stealing.


The thing is, an ewallet provider I don't trust, and stick just a few coins in, then it is only those coins that are at risk.  An untrusted backup of a wallet that I will continue to use in the future can steal any coins I ever put in it.

I definitely agree that keeping it all on your device is the more trustworthy option.  That's not what you've done though.   You've uploaded the wallet to the cloud.  So now I can't trust the wallet on my android phone.  People need to be aware that your choices have already compromised their wallet.  When you eventually add encryption, then you can't just encrypt this compromised wallet -- it's too late.  A new wallet needs to be made and all the coins in the compromised wallet transferred to it; and the compromised wallet deleted.

I'm sorry to be so dramatic about it; but it really doesn't sound like you appreciate what you've done.

If you want an example: there is a strong possibility that allinvain's story of $250,000 stolen from his wallet happened because he uploaded it to dropbox.  This android application has just done exactly that automatically.

This app has lots of potential for the future; and I think it's great.  But with this cloud-backup code in place, average users (who won't know the danger they're in, or how to fix it in the future) should not even be installing it.

^this


What are you waiting for, Christmas?  :D

It seems cool but there are so many data to download.. i think it's no that possible for long.

What happens if i use it on 2 phones? I guess the wallet backup will get messed up if i use the same google account on both phones, right?

Also interested in an answer to this. Would using it on two phones clash the sync process or would it just sync two different wallets?

Is it possible to play with this on testnet?

Did anyone figure out where the wallet.dat file is stored on the phone yet? Mine started forceclosing all of a sudden, and I want to back the wallet up before uninstalling and reinstalling the app, just in case when I uninstall it wipes my wallet with the brand new shiny Bitcoin in it :/

Looks very cool - will add to my phone tonight.

This is a great point, and we'd most likely force the creation of new receive addresses (and therefore keys) as part of an upgrade.  I believe this would solve it no?

You can also just uninstall the app (sending your coins somewhere safe first) and reinstall a new copy once encryption comes out to get brand new wallet.

We certainly don't have it all figured out yet.  Thanks for bringing this up.

We actually haven't tested this yet.  In theory it should keep the wallet synced between the two phones correctly (Android is pretty good at this in general).  But I can't say for sure without testing it first.  Some additional logic might be needed.

No, we don't currently have an option for this.  But you could build a testnet app using the source from github (if you have an Android development environment setup with Eclipse etc): https://github.com/barmstrong/bitcoin-android

There is a simple boolean flag in ApplicationState.java

We should probably put up a testnet version on github or the Android Market.

No transaction fees are added.  Would be a nice option.

Yes it keeps the wallet on the phones internal memory.

Could anyone post a link in this original Android thread to send folks over to this thread?

http://forum.bitcoin.org/index.php?topic=1812.120

Being eligible for the bounty would obviously be nice.  Thanks!

This is kinda cool, Wired just ran a piece on it.

http://www.wired.com/gadgetlab/2011/07/bitcoin-android-app/

How do I know that it's actually making progress downloading the blockchain?  And why not have a regularly updated app that is really just an archive of the blockchain headers?

I'm actually trying to determine that.

Woooooooow! How I wish I have an Android. planning to have 1 though hihihi.

You'd have to make sure you blanked all the pre-created addresses too; and of course that you didn't overwrite existing addresses which might have credit on them.  Then warn the user that they should transfer all the credit they have on those current addresses to one of the new, safe, ones.

That would probably do it.

I do like the idea of a wallet that is part of my google account; but I don't trust google enough to put real money in a place where I have to trust every employee who has access to their cloud storage (which will be a huge number of them).  The ideal solution then is a shared wallet with strong encryption using a password that I have to enter before sending any bitcoins.

It's still not perfect because you're relying on computing power never increasing sufficiently that your current secure password becomes insecure in the future.  Therefore you also need an option to not share the wallet in the cloud, and allow me to back it up manually should I so choose.

If you want to play on testnet, you should try Bitcoin Wallet for Android:

https://market.android.com/details?id=de.schildbach.wallet

It is open source, you can compile it for prodnet as well. I am searching for developers, translators and testers:

http://code.google.com/p/bitcoin-wallet/

Cheers,

Andreas

I was hoping for a directory, like /etc/....

This program looks awesome!

But the 'backup wallet to cloud' feature is exactly what will stop me from using it yet.

Am I wrong or do they have this part backwards??


The phone that 'pops up' a QR code would be the receiver.
The person scanning a QR code would be the sender.

You would be correct.

Nice app!

This is really sweet. It's exactly the kind of thing that will bring Bitcoin to the masses, making transactions really simple.

Thanks for your continued work on this OP.  ;D

How long does it take for the payment to get processed?

I'm thinking of using this in a shop. You need payment processing in less than 3 seconds.

Has anyone been able to get this to do any more than spin?  Mine has been running since yesterday, has a 22 meg footprint, and still hasn't seen the coins that I sent it.  I'm using a Samsung Intercept, but it doesn't force close like Bitcoin Wallet did.

When it was working (having some issues now), the payment would show up instantly with 0 confirmations, and would even show a notification and play a sound. Confirmations still took the normal time-to-find-a-block amount

Mine took about 5 to 8 hours to finally finish spinning (I had to keep the app open and running for a long time). It started Force Closing the next day though, which is upsetting, since it worked extremely well when it finished spinning.

How large was your data footprint by the time it stopped spinning?

Yeah we really really need a block status indicator to help those of us who have been spinning for several hours troubleshoot.

iPhone Plz.

Left it running for 9 hours last night. 4KB data footprint...

Sadly, I haven't tracked the data footprint (unlimited plan here), but the total file size is about 14megs for the block chain, and 24.19 megs for the whole thing

The force close is only because there was an incompatible wallet format change. Just remove all data with the app manager, and you'll be set.

FYI, I just implemented a progress in percent for block chain sync (see notification bar).

(https://market.android.com/details?id=de.schildbach.wallet)

BTW, "Bitcoin Wallet" works just fine on the exact same phone. Granted, testnet's blockchain is MUCH smaller but still, that was a 5 second delay and this has run for hours...

Excellent.  Now how do I safely upgrade, without nuking my phone's wallet.dat?  The market doesn't show this as having an update available.

Can I recommend a feature?  If the phone is out of range of the network, or otherwise does not have Internet access, could this app use a shared wifi hotspot as an intermediary without access to directly transmit the transaction from the sender to the receiver's phone?  Much like your 'Blinkendroid' app can send data to numerous phones if they are all connected to the same hotspot?  This would permit users in the same place to transact so long as there was something like a pirate box available.

http://wiki.daviddarts.com/PirateBox

Excellent idea? Are you aware of a standard?

I would think about transmitting the receiving peers address in the QR code, but then again the BitcoinJ framework currently does not allow incoming connections. I'll work towards it.

I have this app on my galaxy, Tons of potential.  however there is a disclaimer on the bottom of

WARNING: this is entirely experimental. you *will* lose your Bitcoins associated with this wallet! Use at your own risk, and use only with small amounts of bitcoins.

that makes me very wary of doing anything with it.

You're right, they have it backwards :)

Thank you!!

I installed it and it took forever to download the blockchain. I had sent two small transactions while it was downloading, and they finally showed up when it finished downloading. So now I wanted to see how instant the transactions were once it was up to speed. So I sent another transaction, it has 159 confirms on my computer, it's been over 24 hours, but it still hasn't shown up on my phone. In addition, I've sent two transactions from my phone to my computer, and they haven't shown up on either. The little circle is spinning (and has been for some time) but I don't know why. The blockchain file doesn't seem to be getting any bigger. I'm using an LG Optimus.

Awesome. Increadible.
 I expect that people at Google are going to make something even more valuerable with bitcoins...

My bitcoin wallet loss has finally prompted me to root my android (glad I did, and I guess something good came out of the loss). On a rooted android, it is possible to use Titanium Backup to back up the wallet and export the wallet file. Tested by wiping my bitcoin app and all associated files, reinstalling, restoring backup, and my coins are still in there. The wallet file is called prodnet.wallet btw, and is stored in the \data\data\com.bitcoinandroid\files folder. That folder is inaccessible unless your phone is rooted. It would be very usefull to be able to export/backup that file to another more accessible location from within the program itself for those who aren't willing to spend 3 risky hours rooting their phone.

I think it's probably advisable to only keep a small amount in a mobile wallet, not only because of the current lack of encryption, but because mobile devices are more easily susceptible to theft and loss.  I suppose you could employ other measures such as regular backups and remote wipe capabilities.  But still, in most use cases, I expect a user would only want a few bitcoins on his person anyway.

Keep up the good work developers!

Awesome app.  This is why I wish I had an android phone.  Is there anything like this available for iphone?

There is a solution to the theft-of-phone problem.

Provided there is any sort of password (i.e. one that would need hours rather than seconds to crack); what you would do is store a copy of the private keys on your home computer (or any other place really), then if the phone got stolen, you leg it back to your home computer as fast as possible and move all the coins to an address not on the phone.

This is actually one of the biggest advantages of bitcoin, I think.  If your real wallet gets stolen, with actual cash in, it's game over.  At least with bitcoin you've got a chance to steal it back before it gets spent.

+1. Exactly.

I have figured out why mine wasn't working.  The sleep mode was interupting the download.  If you are having this problem, plug your phone into it's charger, open the app, select 'refresh' from the settings menu, and then set the phone down near your wifi router and go to bed.  DO NOT hit the button to sleep the screen.  The app should have marched through the blockchain by morning, and daily updates only take a minute or so.  Also, after downloading the blockchain and finally seeing the coins that I sent it, I sent it more.  It took less time for the phone app to see the transaction than it took me to pull my finger from the mouse and pick up the phone.  Less than a second.  It was "pending" (not unconfirmed, I think that I like that description better) of course, but it knew that it was there.

What a great idea, I'm opening market right now...

I need to get the android first, rofl.
Been wanting it for the past few months.

That's what she said.

j/k.
It's the client, and a large chunk of the block chain (even at headers only, I imagine that gets pretty big)

I wish this was my experience. Is anyone else having severe problems with this not sending or receiving Bitcoins?

i don't know i never could get this app to work right on my G2

Any plans to do a iPhone app?

i couldn't get it to work last week either -
on galaxy s, removed ALL bitcoin related apps and reboot -
installed this first and works fine. Miner widget and mtgox price thingy added, all still working today ;D love it

That's what I was wondering as well.  It would be nice to see a iPhone app then BitCoins could truely be on to a popular route.

@bitcoinandroid great achievement. Now I wonder if anyone is working on an i^*Randomword and WebOS version.

The only problem with an i^*Randomword version is that if Apple allowed it, they would probably want a 30% cut of all transactions *evil grin*

^*Phone/Touch/Pad/etc...

Works great on my Virgin Mobile prepaid $25/mo Samsung Intercept. Well done.

Hi All,

We just released a version 1.1 with some fixes.

- support for up to 8 decimal places
- progress window shows status downloading blocks and connecting to peers
- fixed (hopefully) two bug causing crash reports
- added Russian, German, and Simplified Chinese translations (contributed by the community)


You can update it from the Android Market.  Or if you haven't installed it yet visit:
https://market.android.com/details?id=com.bitcoinandroid&feature=search_result

We also added the apk files to the Downloads section here if you don't have access to the Android Market:
https://github.com/barmstrong/bitcoin-android/archives/master

There is a testnet and production (regular) version there.

Its about time this is awsome!

I saw this, does it work with my current wallet?

No, they are both implemntations of the bitcoinj lightweight client on android.  Pretty much work the same, different UI.  I have them both, now.  They both seem to work fine on my Samsung Intercept, but they both take some time to download the blockchain.  

Beware, however, there is now a third such client knockoff on the market, and it could be a scam

I installed the app in my SD but the blockchain seams is downloading to the internal phone memory, it stoped downloading at 22% and it only continue if i unisntall apps from my phone or move them to the SD card to make more space for the block chain, but it never end the download, I have 3.19 GB of free space in my SD and can't download the full block chain :(.

Somethings seriously wrong, then.  Mine is on my SD card, and my SD card is only 2 gig and does fine.

Looks really cool I would really like one made for webOS though any news on plans for that yet?

Not unless you're doing it.

A BTC Bump function would be nice like in the paypal app :-)

Wow this is going to be great and very useful. Checking it out right now.

I moved bitcoin from my MtGox Android to my Bitcoin Android wallet. It worked. This is very promising. I showed it to a local bar owner and explained the potential of bitcoin. She seemed scared, but liked the fact of no transaction fees. We are almost ready to break this out as a complete POS. Now where can I get "We Accept Bitcoin" stickers?

Sweet sounding app! I'm trying it over lunch.

I would rather say that "there are low transaction fees" instead "There are no fees"

Very cool! Appreciate it!

I second this movement.

How is this different from the "Bitcoin Wallet" already on the market.

Bitcoin Wallet is awesome. We need more apps. This is an open source project, so I hope that developers are collaborating on projects. There are a lot of great ideas out there.

I'd like to import my wallet.dat file from my computer onto my phone, is that possible?

Or send what you have in your wallet to the new Address on your phone.

Well I'd like to just have the same wallet.dat file on my phone and computer. Mainly so I can monitor if I get any BTC sent to me while I'm out of the house.

oh.good new,am android user! i'll try it! :)

Impressive work. Please keep this up :) I sent you a donation.

yess!!!!! thank u so much for dis

I just recently got a Droid and I downloaded this app to it. I was able to receive bitcoins on it but now I'm having difficulty sending them back out. It appears to want to use a QR scanner to get the bitcoin address to send to. I used a qr code generator and input the text of an address but when I scan it, the app says it's "not a valid address". What am I doing wrong?

thanks for your great job.

Thanks for creating this new software!

I will be sure to try it out and then tell you what I thought!
P.S Hopefully the blockchain will download quite quickly!  :)

YSoliman

Thanks for posting this in the newbies section, was getting bored here ;)

Great post, great app, great way for noobs to have a wallet! haha

Hopefully be implemented in all parts of the world, at least in my country is not even close.

I'm looking forward to installing this on my android cell phone

I think this may be a problem with the scanner in Bitcoin Android. Only a grey screen is displayed. It picks up the four corner dots and says not a valid bitcoin address. Has anyone else experienced this?

if your phone sleeps automatically you can setup so that it stays on when charging which i dont think is the default

Settings>Applications>Development>Stay Awake

Looks pretty awesome.

I've been waiting for this:

$80 Android Phone Sells Like Hotcakes in Kenya (http://singularityhub.com/2011/08/16/80-android-phone-sells-like-hotcakes-in-kenya-the-world-next/)

Hope the app will run.  If so, this could make a real difference.

Ok. So it looks like I'll have to manually get these btc of my phone. Does anyone know how that might be done. From what I read earlier in the thread, I may have to root my phone to get access to the file. That may be a problem. Any suggestions?

I wish iPhone developers would create something like this.

Bump

This thread needs to be moved out of the Newbies section.


I've been running bitcoin-android on my Droid 3 for a few days and it works great!  Just playing with small amounts still, but IMHO this has huge potential for being a driving catalyst for greater adoption.

Thanks very much for putting out this Android app. Looking forward to having a "slush fund" bitcoin wallet separate from the desktop wallet I'll want to encrypt and project from trojans and such...

Curious to know if the wallet.dat file on the android itself is obfuscated or encrypted? I'd hate to have it snooped out by some totally unrelated nefarious application and mailed back to the mothership...

Wow. Awesome! Works great!

This definitely needs to be moved out of the newbie section.

With several bitcoin android clients available now, is there any good comparison table somewhere?

If I can avoid reading 6+ pages of thread on each and every implementation that would be good.

Does this one store the blockchain on the phone?

You should get Bitcoin Wallet on the Android Market

Just finished trying out the app - great interface and features!
Look forward to using more in the future!