Quite nice to see that this is written in Haskell.
The idea of a bitcoin app that stores funds in another currency makes a lot of sense for people who primarily want to use bitcoin as an exchange mechanism without speculating on its future value.
I'm curious what service this uses to purchase bitcoins, or if it uses its own exchange; it's not comforting to see a reference to the MtGox API, but hopefully they're only used to find out the current value. (Even then, they're not a reliable metric for the true value of bitcoins, since they're not sufficiently liquid with respect to governmental currencies, but that'd still be better than actually attempting to use them as a currency exchange.)
this is awesome!
btw if you plan to make an iOS app, maybe you'll be delighted to know that you can apply as an open source developer to free Xamarin licenses: http://resources.xamarin.com/open-source-contributor.html
(I guess writing F# would make you happier than ObjectiveC, given that you wrote your server side in Haskell ;)
This is great. These kinds of open sourced production apps help people adapt more of haskell.
Some background: It's an Android wallet, where you maintain a euro balance (held by Bridgewalker for you). Using those funds, bitcoins will be bought at current market price whenever you want to send any. This allows you to use Bitcoin only as a payment mechanism, without being affected by the exchange rate volatility. You fund your account via Bitcoin as well, which will be exchanged for euros at current market price and credited to your account.
So: Bitcoin as transaction mechanism, Euro as store of value.