Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Crypho - End-to-end-encrypted messaging and file sharing
NotifyXF - Send notification to yourself in Telegram
blockslack.io - Chat for small teams — encrypted and decentralized
Talla the Task Assistant - A.I. task-list manager built for Slack
Wire by EY - A highly secured collaboration platform