Signal is the world’s most widely used truly private messaging app, and our cryptographic technologies provide extra layers of privacy beyond the Signal app itself. Since launching in 2013, the Signal Protocol—our end-to-end encryption technology—has become the de facto standard for private commu...
If you need to convince your friends to use some app it might as well be XMPP compatible instead of another walled garden. If you can get your friends on board, you win, even if nobody else uses it.