Briar is peer to peer via Tor. This has pros and cons.

Pro:
-Everything stays on your local device
-Uses Tor Onions to avoid government domains
-It can do bluetooth to bluetooth, for like an in-person protest for example

Con:
-UI sucks
-Other person has to be online
-You can use mailbox drops to host a server, but then it’s really just like XMPP over Tor
-Group chat user interface is horrible and confusing