I played with @delta and *damn* is it sweet!
It uses my e-mail account as transport, but encrypts using OpenPGP, and feels like IM. Has groups and all.
It's not exactly a @signalapp replacement (yet?): a). it obviously leaks metadata, as it uses e-mail as transport; and b), it uses Autocrypt for key exchange and I have not found a way to *pin* known keys for certain accounts.
But it's interesting! I will keep an eye on it; 
saga shows why we need to move away from walled gardens.
To be fair, signal also leaks metadata of the form of which-ip-talked-to-which-ip to signal the service (but signal the service promises to throw it away immediately). This case is both worse (because there are more entities involved) and better (because metadata is leaked only to entities somehow related to the sender and recipient as opposed to some single entity that cannot be avoided).
@robryk yeah, fair. #ItsComplicated
What I really wish is for @briar to have store-and-forward and an iOS client. But that's not going to happen anytime soon, as far as I understand.
@rysiek @briar @delta @signalapp
BTW. This complicated thing about metadata is the main reason why I have misgivings about the "stories" in signal: they would create conversations between each of their users and ~all their contacts, which would show more of the social graph to anyone with ability to monitor what signal the service is doing.
@robryk good point. I have other problems with Stories in Signal, but that is definitely worth adding to my list.
I've done a thread about Stories before, can't be bothered to repeat right now.