[silur]

It is. I've tested, overviewed the code and packet-sniffed several self-claimed anonymous and secure chat apps, tox was in a tie with signal and telegram with security, and first place for me with anonimity. The toxCore philosophy (isolating the protocol tools from the client) is a big plus too, you can create your own client or integrate tox to your app however you like. The sodium crypto library is really trusted and easy-to-use (less control but it's more failproof than openSSL primitives), it's based on the NaCL library written by the creator of Salsa20/Chacha20 encryption Daniel Bernstein.