We've used telegram e2e but its frustrating since you can't see those chats on desktop at all. (for obvious reasons)
No login. No password. No app. All WebRTC. Chrome required since Firefox does not yet seem to support encryption over WebRTC (I think).
I set it up from scratch with Debian Linux and Virtualbox in about 30 minutes here: https://www.youtube.com/watch?v=4rlffwHUchk
We've used telegram e2e but its frustrating since you can't see those chats on desktop at all. (for obvious reasons)