Thursday, June 29

Things Change Fast – Apple Allowing Bitcoin Wallets On iOS

Just under three weeks ago, I’ve written about web-based bitcoin wallets that worked on iOS.

Guess what? Apple has meanwhile clarified their rules (see item 11.17 in Apple’s 2014 App Store Review Guidelines), basically allowing bitcoin wallet apps back into the App Store.
So whatever I wrote three weeks ago isn’t true anymore, so I better follow up with a first quick review of some of the native iOS apps that are available in the App Store:
(Note: I personally don’t recommend putting any serious amounts of btc into any of these wallets, I’d give them some time to see how they fare and age)
1. CoinPocket – used to be web only, now a virtually identical native version is available in the App Store. Still a single address wallet. The web version used an external QR code scanning app, the native version has the QR scanner built in. The term “native” is a bit misleading, because the developer has taken the web version and runs it inside a UIWebview. As a result, some of the crypto operations (calculating the BIP38 encryption) can take very long because UIWebview under iOS 7 doesn’t have access to the speedy javascript engine that Safari has. This should change in iOS 8. Even though the operation took over 5 minutes on an iPhone 5 during testing, make sure to export the encrypted private key and save it, in case the wallet gets lost during a reset or update. At this time CoinPocket only shows balances in BTC or USD.
Verdict: fast and works well for smaller amounts, can sweep private keys in different formats, but much too slow during some of the crypto operations, only supports one address and one currency conversion. The addition of EUR rates would be much appreciated.
2. bitWallet – was native before, but has now been updated with native transaction sending, so there is no more requirement to copy/paste the signed raw transaction. Even though it can now send transactions, sweeping of private keys is still missing. You can add one, but there are situations where sweeping (e.g. sending the entire balance of a private key to a new address) is clearly the better choice. bitWallet lets you compose a transaction with multiple recipients and amounts, so you save on transaction fees. You can also create as many addresses as you like and it allows you to build watch lists to keep an eye on other addresses.
Verdict: great design, multiple addresses, unfortunately no sweeping of addresses possible. Also not clear how to backup keys other than manually copying them out of the app or printing paper wallets. Still one of my favorites at this point.
3. breadwallet – this app hit my radar only the other day. It’s very simple, but has a few nice features. It for example gives you a “pay address from clipboard” button instead of making you manually paste an address into a field. Simple but genius. Also when you tap the receive address in the app, it allows you to copy it to the clipboard, compose an email with the address or send it via SMS (even though that also allows you to send it as an iMessage). Unlike CoinPocket, breadwallet is a deterministic wallet (BIP32) that generates a new receive address for every transaction.
breadwallet is a single address wallet like CoinPocket.
Verdict: has some smart features, but only shows balance in the unusual bits.
It’s only a one-address wallet and Generates new receive addresses for each transaction, but doesn’t have any advanced features like sweeping private keys. (Correction: you can sweep keys, but you do it in the “send” tab, where you enter the private key instead of the recipient address. A plus for having the feature, but a minus for making it virtually impossible to discover.)
A note on BTC vs. mBTC (a thosandth of a bitcoin) vs. bits (a millionth of a bitcoin): as long as the community cannot agree to a standard (and I doubt they will anytime soon), I think wallets should be configurable. If someone wants to display their wealth in Satoshis, then by all means let them.
Honorable mentions:
– to my knowledge the native version of the multisig (P2SH) wallet has been submitted to Apple for review and should be out soon.
– according to a tweet by Nic Cary (CEO, their iOS app is in the making too.
– australian Coinjar have their bitcoin app in the App Store, albeit not on the US market – and it’s also not a real wallet app, but a frontend to their web-based wallet
– same is true for the Coinbase app, which has just come out in the App Store and spurred quite a bit of controversy
Did I miss anything important? What’s your favorite iOS wallet and why?