I have nothing against Signal. I just don’t have access to a phone number right now. I fully intend to use the Signal when I get a number. I know there is no silver bullet, no absolutes in the privacy world but I’m looking for any messengers that are generally considered to be private and secure on Android that I can try to convince my friends and family to use. I have a mid - low threat model, it’s just the thought of giving the Zuck anymore of my family’s data makes my skin crawl.
ive heard briar and session are good
You could try Session. It makes a session ID like this . This can be used to contact people or for people to contact you. I’ve used it to talk to my SO a bunch of times.
XMPP. It’s an old standard, there are servers you can get an account with or you can host your own. And with OMEMO encryption everything is end to end encrypted.
Aside from signal I would say your options are Simplex or Briar.
briar is pretty decent. no voice/video, but solid and quite private with multiple ways of getting messages out in hostile network environments.
edit to say: its also completely p2p using Tor rendezvous points with no centralization at all.