Bitcoin Forum

Brian Armstrong has released Bitcoin for Android as a free and open source application to the Android Marketplace (https://market.android.com/details?id=com.bitcoinandroid (https://market.android.com/details?id=com.bitcoinandroid)).

It's a very slick way of sending and receiving Bitcoins on your Android phone. Easy install, but make sure that you do it over Wifi since it provides a recent block chain to get you up and running quickly, and that's a few megs.

Technically minded folks who want to examine the source code to verify that it's not going to rip them off can do so at GitHub (https://github.com/barmstrong/bitcoin-android (https://github.com/barmstrong/bitcoin-android)).

Receiving coins can be done by instant QR code generation (so another phone can view the screen and pick up the wallet address), or by sending the wallet address via almost any mechanism you can think of (SMS, email, Twitter, Facebook, FriendStream etc etc). It will copy the wallet address to the clipboard if you want to allow you to paste it anywhere you like.

Sending coins can be done by either scanning a QR code (ideal for merchants presenting prices in BTC) or by manual entry (from clipboard if necessary).

It's really aimed at keeping pocket change available for small day to day transactions since your phone could be stolen (just like a real wallet could be picked) and for that it's an excellent choice.

Give it a go and continue to build the Bitcoin economy - the merchants need you :-)

Wow, that's awesome  :D

New era has begun!

this is awesome but I'm wondering, how can I make it use the testnet (your screenshots have testnet addresses)?

Have raised an issue with the development team for you: https://github.com/barmstrong/bitcoin-android/issues/7 (https://github.com/barmstrong/bitcoin-android/issues/7)

22 Mb?  OMFG!

Hence the Wifi recommendation. Remember, it does include a recent block chain.

I'm not worried about my data plan, I'm worried about the very limited amount of internal memory on my HTC Desire…

Cheers,

From the application wiki (https://github.com/barmstrong/bitcoin-android/wiki/Technical-Details (https://github.com/barmstrong/bitcoin-android/wiki/Technical-Details)):

"It's a full bitcoin client running on your phone. This means it keeps its own copy of the blockchain (currently about 14MB) which we store on your phone's SD card, and it doesn't need to communicate with a centralized server. Most phones have large SD cards (8GB or more is not uncommon) so storing 14MB isn't too bad. The wallet file is stored on the phone's internal memory instead since it quite small compared to the blockchain. We include a recent copy of the blockchain in the actual app package that you download from the Android Market so you don't need to download and build the whole thing from scratch. The first time you run it, it will contact nearby peers and update the included blockchain to the most recent version. This usually takes a minute or less over WiFi. After that, updates to the blockchain and transaction notifications should be near instantaneous (a few seconds) over 3G or WiFi."

So it should be dropping the blockchain on your SD card, not the internal memory.

You guys are changing the world...

All right, I installed the creature, and it does seem to drop the blockchain on the SD card.  However, it still takes up 2.20 MB of the internal memory — and since a wallet is continuously growing, this is amount is likely to increase.  I'm not convinced it's such a good idea to store the wallet in internal memory.

Cheers,

I really hope this catches on.  Awesome. Damn, I may just go out and buy a cellphone so I can use this.  (Yes, I have never owned a cellphone.)

Seems like a fair point for older smartphones. I've raised an issue for it (https://github.com/barmstrong/bitcoin-android/issues/9 (https://github.com/barmstrong/bitcoin-android/issues/9)).

Awesome. Sent 0.01 BTC to myself and it showed up on the phone, still waiting to be cemented in a block.

Put a USD/BTC calculator on there so I can calculate how much I owe my friends for dinner and I'll pay them in bitcoin.

Already requested by someone else: See https://github.com/barmstrong/bitcoin-android/issues/5 (https://github.com/barmstrong/bitcoin-android/issues/5).

Please add your name to the list of interested people.

Virtual Transactions: Another Step Forward

http://www.chicagotribune.com/business/breaking/chi-ebay-buys-zong-as-mobile-payments-gain-traction-20110707,0,5444610.story

Better put a EUR/BTC calculator in there. there are much more people in the EU than in the US. Also the USD may be dead before the EUR is gone.

Noob question - On my PC the "block chain" data file is several hundred megabytes. How is it only 14mb on this mobile version?

Beautiful.  Now I have an excuse to finally get an Android phone.


Let's hope people take heed of this before we have a rash of losses from mobile devices.

From the description:

doesnt that mean I could pay something offline and after that somehow delete the queued transaction? At least with a little code modification? Who would trust such kind of payment?

Actually there is a need for a delete queued transaction function: when paying in a store and realizing beeing offline too late, the store might not accept my offline-payment (for reasons mentioned above) and then surely I dont want the transaction beeing completed later...

This is a great development. But they should consider making it a light-weight client as soon as possible.

Another addition I'd find important: allow the user to configure proxy access, so that one could put the application behind Tor. I think it's particular important when accessing the bitcoin network... you don't want to tell the whole world "hey, there are bitcoins on this IP, come and get them!"...

impressive.

Will

I'm looking forward to looking at certain parts of the source that I'm interested in. This is definitely a boon for people like myself having trouble with the sources of the desktop client. I spent a good amount of my weekend just trying (and failing) to compile the desktop client. This should have the code I need to move forward with a project I've been thinking about and will hopefully be a part of this client in one form or another in the future.

they are well aware of the issue and 14MB is already crazy compared to what you have on your PC ... as evoorhees found out :)


they use a compressed format and rely on connected nodes for validity. (please correct me if i'm wrong.)

15MB is already ultra lightweight for a bitcoin client. If you want to have a real thin client use something like an instawallet client or a bitcoind remote control. both exists on android already.

that is totally cool.  When is the iPhone version coming out?

Mine started ForceClosing suddely this morning. Anyone know where the wallet.dat file is stored on the phone or backed up to? I need to reinstall the app, and am worried if I uninstall it, I may lost my single freshly mined Bitcoin.

uhm ... :)))

i tried "bitcoin wallet" for android and for a reason it only runs on testnet. they both share the library bitcoinJ. If the crashes were from bitcoinJ not working right yet, I wish you good luck.

https://github.com/barmstrong/bitcoin-android/blob/master/src/com/bitcoinandroid/WalletBackupAgent.java looks like it does backups to google so a total loss is unlikely and (i think) reinstalling should not affect your saved wallet. At least the code reads as if it tries to restore from the cloud in case your local wallet has a balance of 0 which should be the case unless you accidentally created a private key similar to an existing key with a balance ;)

First thanks, I think this client is a big step in the right direction, but it seems it still has some flaws:

I send me a money request by mail and send sent 0.01BTC to the android client in order to try it. I did this 8 hours ago, the transaction has 76 confirmations but it still has not appeared in the android client. I have tried to turn off WLAN and only use 3G in order to make sure it is not a firewall problem, but nothing so far.

What can I do? Is there any way to get hold of the wallet of this thing? Or make it somehow rescan the blockchain?

BTW: accidentally posted the same question already on another thread, but I think this one is the right one to ask.

If you haven't tried it yet, there is a "refresh" button in the menu. Maybe that will work.

I hit the refresh button already a couple of times and it seems to do something, as it is just sucking up my data flatrate. But still no visible transactions.

I'd guess you haven't paid much attention to the news, lately.

I have the same problem - and when I checked application Details it is only 2.01MB - so something is very wrong. It looks like the blockchain isn't saving so it doesn't see the transfer, even though it is using the data connection.

Any ideas?

This is already implemented by Bitcoin Wallet for Android. (see signature for Market page)

Application Details tells me a similar story, but by diving into the sd card I can see the file in the secured android apps directory, and it weighs in at 22 megs right now for me.

This is almost enough reason for me to buy an android device.  I have been quite happy with my iPhone but this is something I really want! 

Finally found the blockchain file but mine is at 400K, right where app details says it is, and it doesn't grow when I let the app sit and run.

Earlier today I sent a pull implementing this feature.  It can convert between all traded currencies.  :)

https://github.com/barmstrong/bitcoin-android/pull/17

Where exactly is the file?

found it /mnt/sdcard/Android/data/com.bitcoinandroid/files/ on my G2x

Anyone with a working version of this app, what is the current/correct size of the blockchain file? thanks. I seem to be stuck at 12.32MB - I do think it hangs when switching wifi/cell/wifi maybe, but I can't seem to get the download re-started, even with force quit and refresh. Stuck 12.32.

Does the app allow you to select transaction fee? And what about wallet encryption?

Is there a somewhat standardized USD/BTC exchange rate, that is indexed over *all* of the exchange sites rather than just Mt.Gox?

As more merchants adopt bitcoin payments, it will be helpful to have a single reliable exchange rate that can be grabbed from a known location.

The 1-day weighted average for Mt.Gox is available from the Trade History tab at bitcoincharts:
 http://bitcoincharts.com/markets/mtgoxUSD_trades.html (http://bitcoincharts.com/markets/mtgoxUSD_trades.html)

That is a decent estimate, but we really need a weighted average over most or all exchanges (we need to decentralize this critical function).  The smaller volume sites won't have much impact on the weighted average right now, but implementing this now will allow a smooth transition as sites like TradeHill and Camp BX gain market share.

Wait, is the value reported on the front page of bitcoincharts.com and in
 http://bitcoincharts.com/t/weighted_prices.json (http://bitcoincharts.com/t/weighted_prices.json)
the indexed rate over all exchanges?  If so, that guy is totally awesome, and i'm totally hitting him with a big tip.

I can confirm that reinstalling the app WILL erase your own wallet, and WILL overwrite whatever backup you may have in the cloud, so unless Google has an older backup of the wallet file and can give me access to it, these 2 coins are gone for ever as well
http://blockexplorer.com/address/1DWwhv9Kg3SE9GBX7Kk9A11nw3B3MUBe2t (http://blockexplorer.com/address/1DWwhv9Kg3SE9GBX7Kk9A11nw3B3MUBe2t)

Not TOO upset, since these were mined and I have plenty more, but, still, it's money lost :'(
So, PLEASE make the ability to back up a wallet to the SD card or computer a HIGH priority!

(p.s. reason I had 2 on there is because I was hoping to go shopping in NY for some food)

Actually, it seems that UNinstalling the app erases the wallet. Android by default removes all of an app's saved preferences from the internal phone memory when the app is uninstalled.

15MB today, but if it intends to store the entire blockchain, as well as receive and propagate every transaction, how much resources will it be consuming in the near future? Bitcoin is growing exponentially.

My experience. HTC Magic ...

App downloads and installs as quickly as most other apps.

However, seems to take some time to download the compressed blockchain and needs to be left as the running app to do so.

Checking through GitHub project I see these are all raised bar the download rate, which I guess is a result of every man and his dog currently trying to ;O)

Will update once I've managed to receive and send - going to wait the the blockchain download to complete first.

Ok so I was messing around with this app and Bitcoin wallet, and trying to send coins back and forth just to test it.  For the most part things worked well, except when I was a bit of an impatient dufus, and sent some btc back and forth within a block or two.  The Bitcoin 1.0 app didn't see the transaction, even after a few blocks (and block explorer confirmed that it was put into an earlier block), so I sent the remaining BTC to my Instawallet, quit the app and used Titanium backup to restore the data to a previous time.  I then opened it and tried to re-download the chain, but it's not showing the transaction (or the money sent out to Instawallet).  So now it thinks it has more BTC than the address actually has.  And I can't send out the amount I know it has because the transaction is invalid (since it tries to send too much back to itself).

So is there a way to have it re-scan the block chain?  Or can I somehow get my private key for that address?  Basically, is there any way to recover the btc for that address?  I feel like there should be since the program obviously has to have the private key, but I'm not at ALL tech-savvy enough to know what to look for or how to go about the recovery...

I just downloaded and installed this.  Unlike the bitcoin desktop client, how do I know how much of the block chain it's already downloaded?

You don't. Bug / design request has already been raised on the GitHub page for the project.

I had sent .01, another .01, and when these worked another .98 (a week ago today). The .98 never showed up so I tried sending the two small transactions out, but this didn't work either. I tried letting the app sit open without sleep mode over night to update, but it never worked. I backed up Bitcoin with Titanium Backup. I then uninstalled Bitcoin and THOUGHT I was clicking to open Titanium only to realize I clicked on it to uninstall it and I too have now lost my Bitcoin. I'm going through the whole process of downloading the blockchain again and hoping it works this time.

So the wallet data is stored in the cloud? So if I uninstall it that's all gone.
I guess if you got a new phone or reset your phone, as long as you log in with your google account you should be able to retrieve said wallet?

but will this generate bitcoins faster than my 2007 laptop?

Possibly. Unless you meant 2,007 laptops. In that case, you're probably Best Buy and should start accepting Bitcoins.

I would not trust it. My copy created a new wallet and overwrote the one in the cloud.

Use Titanium Backup, and copy the backup file from the SD card to your computer. That may require a rooted phone though.

Yeah, I'm not going to keep anything more than maybe $30 in BTC on it for sure.

Seems others are having issues downloading the blockchain too. Mine just seems to be downloading really slow and stopping/starting randomly. Currently at 14.619mb and slowly going up.

Hi there,

I'm the creator of BitCoinJ which this app is based on.

It's really early days for these mobile apps yet. Expect slowness, instability, bugs and losing of coins. All the issues reported in this thread are known and we'll implement solutions eventually. Until then accept that you're on the bleeding edge and from time to time, that means you'll bleed.

[Awesome -- registering to this thread for updates]

I updated today and am getting status bars. Is this new? Or did I just not update my last install?

So where is the wallet on the phone? I want to be able to back up my wallet myself.

I have the same question.  I have some coins in the wallet, and now the app keeps closing itself without letting me in.  I'd like to move the coins to another android device, but where is the file?

Hi guys, sorry for the delayed response on this!  Have been seeing a number of reports about people having trouble backing it up or getting coins off the device.  We are investigating a different approach to the app which will hopefully make it more reliable.  I wish we could make progress on it faster, but it's still just a side project for the moment.  As always, continue to treat it like a beta app and don't put any coins on the device you are unwilling to lose.  Hope to have more info soon!

Btw, to answer the question about backing up.  The wallet is stored on the devices internal memory, so I'm not aware of any way to backup this file with the standard usb cable connection etc.  Hope it helps!