Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
qTox - A Qt graphical user interface for Tox.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Tox - Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.
FluffyChat - Open. Nonprofit. Cute ?
start.me - A Modern-day bookmark manager. A place for your favorites. A news feed (RSS) reader. A browser startpage. A portal for your team.