OpenKeychain
About
"OpenKeychain is a free and open-source mobile app for the Android operating system that provides strong, user-based encryption which is compatible with the OpenPGP standard. This allows users to encrypt, decrypt, sign, and verify signatures for text, emails, and files." [1]
Apps Compatible with OpenKeychain
- K-9 is compatible with OpenKeychain and you can contribute to K-9 translations here.
Translate OpenKeychain!
Localization Resources
OpenKeychain Localizer Instructions
References
[1] Wikipedia