FusionAuth - FusionAuth is a CIAM platform that is 100% free for unlimited users.
Keybase Chat - End-to-end encrypted chat built into Keybase
Beagle - Secure your website before hackers break into it.
Cyph - Cyph is the name of a completely free chatting website that provides its visitors with a secure and safe chatting environment.
blockslack.io - Chat for small teams — encrypted and decentralized
Chadder - Encrypted messaging app