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.
yaxim - yaxim Feb 7th, 2013 yaxim (Yet Another XMPP Instant Messenger) is a Jabber/XMPP client with open...
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
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.
Zulip - Chat for distributed teams. Zulip combines the immediacy of real-time chat with an email threading model. With Zulip, you can catch up on important conversations while ignoring irrelevant ones.
Xabber - Open source Jabber (XMPP) client with multi-account support, clean and simple interface.