[Tmpod]

Worth mentioning: https://www.beeper.com/

Essentially a Matrix-powered service focused on bringing a ton of inboxes. I've heard it's great, but never tried it myself.

[Yeri]

https://element.io/element-one -- I'm using a Matrix Signal bridge (meh, it bugs quite often, kicks me out, doesn't properly update keys when people get a new phone). Also does not support calls etc.

[jhylands]

Not currently open to sign up. :( I’ve joined the queue to get an account though

[sdfhbdf]

I joined the queue over a year ago and have yet to receive any communication about signing up.