Have you considered the possibility of integrating delta.chat in openkeychain.org ?
yes, we’ve considered it, but one issue is that OpenKeychain is available for Android only while Delta Chat is multi-platform (and we did not want a different PGP solution on every platform).
however, we’re in close contact with the authors of OpenKeychain as well as with K-9 and there is some cooperation, eg. Autocrypt and also the QR code verification (labs-feature in Delta) is compatible between Delta Chat and K-9.
That’s true, I didn’t realice that.
Excellent work, thanks!