Threema offers reproducible builds as well, for the Android app: https://threema.ch/en/open-source/reproducible-builds https://threema.ch/en/open-source/reprodu

Threema offers reproducible builds as well, for the Android app: https://threema.ch/en/open-source/reproducible-builds https://threema.ch/en/open-source/reproducible-builds Signal too: https://github.com/signalapp/Signal-Android/blob/master/reproducible-builds/README.md https://github.com/signalapp/Signal-Android/blob/master/repr... Regarding the iOS app store, Telegram writes: > As things stand now, you'll need a jailbroken device, at least 1,5 hours and approximately 90GB of free space to properly set up a virtual machine for the verification process. https://core.telegram.org/reproducible-builds#reproducible-builds-for-ios https://core.telegram.org/reproducible-builds#reproducible-b... It's a manual process within a new VM. I wouldn't be surprised if it frequently breaks without anyone noticing. But at least they're trying, I'm not aware of any better approach. Apple's GUI-focussed approach doesn't make these things easy.