Seald - Keep your conversations secure, everywhere.
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Keybase Chat - End-to-end encrypted chat built into Keybase
Crypho - End-to-end-encrypted messaging and file sharing
Keybase - Keybase will be a public directory of publicly auditable public keys.
StealthChat - StealthChat is Encrypted, Private, Secure Calls and Chats on Android and Apple iOS