Session, onion routing no metadata IM
getsession.org
getsession.org
What is unique, is the way contacts are handled - it's an alphanumeric ID you pass to your contact but seems there's a plan to support standard usernames with a fee. Tho, there are also QR codes on profile page you can share with contacts which should make easier adding people.
There's emoji support obviously but no stickers (if someone cares actually about that), delivered/seen messages status and typing, audio messages and spellcheck.
Seems like yet another pretty good alternative but the fact is Australian-based worries me - Oz guys have some issues with encryption law iirc.
Also, it looks like there's no UI language settings for whole app - it depends on system setting it runs on (at least in GNOME case).