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.

OpenKeychain is listed on the official OpenPGP homepage[5] and the well-known developer collective Guardian Project recommends it instead of APG to encrypt emails.

[6] TechRepublic published an article about it and conclude that "OpenKeychain happens to be one of the easiest encryption tools available for Android (that also happens to best follow OpenPGP standards).

[10] In 2016, the German Federal Office for Information Security published a study about OpenPGP on Android and evaluated OpenKeychain's functionality.

[11] OpenKeychain has been adapted to work with smartcards and NFC rings resulting in a usability study published on Ubicomp 2017.