What I want in messaging service:
1) Use multiple clients/devices at the same time
- Multiple client sharing one "address" in Tox is not possible last I checked.
2) Every client receives every message
- Somewhat working with Message Carbons in XMPP
3) Open Source backend/frontend
- Telegram/WhatsApp, HipChat etc are out of the question.
4) Easy to use encryption, also in MUCs (Multi User Chatrooms)
- This kicks out couple of clients that only support OTR messaging that only works one-to-one.
5) Able to send pictures
- Works one-to-one with proper clients in XMPP. No MUC support afaik
6) Video and Audio calling
- Jitsi is the only client where this actually works?
For me these are the most important features. It's a shame that closed source apps are the best bet for messaging right now.