about the "many apps" that do crypto (I guess you are talking only about CryptoText and CryptoWisper?) apps are from 3rd parties, and yes, that two apps are a bit useless to use inside #DeltaChat, you could share the output to other insecure non-ecrypted apps tho, but I also would not trust the security of such apps it is just some amateur trying to create little apps
in any case mini-apps don't need to implement crypto as they benefit from encryption in DC automatically
treefit (npub1t0n…7d8g)