Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Facebook Messenger - Facebook Messenger is a faster way to message.
Keybase Chat - End-to-end encrypted chat built into Keybase
Amity - Amity's Customer Relationship Hub simplifies customer success management.
Crypho - End-to-end-encrypted messaging and file sharing