Demonsaw - Demonsaw is the next leap in the evolution of a free Internet, and the debut of social cryptography.

qTox - A Qt graphical user interface for Tox.

Gajim - Full featured and easy to use Jabber client

Tox - Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.

Jitsi - Open-source video calling and chat platform.

Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.