COI 0.10. comes with a bunch of interesting features. Seems like they are catching up with Deltachat.
Release Technical preview 0.10.0 – Android · open-xchange/ox-coi · GitHub … :
“New Features:
* Added QR code scanning to the “Add contact” flow
* Added a setting to hide invites from the chat list (for anti mobbing / spam). Invites can then be found in the settings
* Added flagging of messages to provide a way to easily find important messages again“