Conversations.im - XMPP client designed with ease of use and security in mind
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.
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Square - Square helps millions of sellers run their business-from secure credit card processing to point of sale solutions. Get paid faster with Square. Sign up today!
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.
Taptalk - Personal video and photo messaging