Was thinking the same thing. This seems better suited for chatting with arbitrary people nearby, but with zero verification of who you're talking to. You don't have to set up an account at all, just install the app and start chatting as @anon<number> or change the username to whatever you want.

And Berty on iOS?

I was wondering about Briar... seems maybe like reinventing the same thing over again although I assume there's some important functional difference I'm not thinking of.

Briar requires manual pairing with users for some odd reason. Doesn't make sense and makes it unusable outside a family context.