Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Chatlink.com - Anonymous communication platform
qTox - A Qt graphical user interface for Tox.
Autocrypt - Convenient End-to-End Encryption for E-Mail
Tox - Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.
GPG Suite - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.