Sorry, I actually got your message on IRC but couldn't reply extensively at the time so I decided to take the time to reply now.
Some mandatory stuff that should be done in the immediate future:
- Implement OMEMO or whatever advanced encryption we can
- Timed messages (which is something very cool that no other app has)
- Backup conversations and groups
- Contact info screen (mainly because of security needs, e.g. fingerprint and all)
- Some UI improvements such as #858, #75, #820, #864
I really like the idea of giving votes in exchange for a donation by the way!
And this is getting really off topic now I'll start a new thread right after releasing 4.0.1 which should happen anytime between tonight and tomorrow morning.