qTox - A Qt graphical user interface for Tox.
Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
Tox - Send messages, files, create groups and make Tox to Tox audio and video calls. Securely.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Toxic - Toxic is a client with an ncurses interface, written entirely in C.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.