Altana - Bitcoin WalletGoogle Play
Our wallet review process
We examine wallets starting at the code level and continue all the way up to the finished app that lives on your device. Provided below is an outline of each of these steps along with security tips for you and general test results.
Application build test result
Update 2022-08-07: This app released version 21.10.13 without updating the source code.
This analysis is based on this issue by Emanuel.
This app is a fork of the currently reproducibleand supports Bitcoin with the same timelock-and-multisig setup as Green.
Altana is based on services offered by GreenAddress.
sounds like the app doesn’t come with their own servers but relies on Blockstream’s servers.
“Their website” has only a small section on the wallet which basically links back to Google Play for details and a code repository is nowhere to be found. But I think Emanuel found this wallet the other way around, by searching GitHub for Bitcoin wallets and so he shared this repo
Emanuel also managed to build the wallet but with plenty of differences to the version from Google Play. Until those are resolved, the app is not verifiable. Check the issue for details.
Do your own research
In addition to reading our analysis, it is important to do your own checks. Before transferring any bitcoin to your wallet, look up reviews for the wallet you want to use. They should be easy to find. If they aren't, that itself is a reason to be extra careful.