Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.

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

File Camouflage - Hide and encrypt files inside a jpeg image

qTox - A Qt graphical user interface for Tox.

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

Chatlink.com - Anonymous communication platform