Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
blockslack.io - Chat for small teams — encrypted and decentralized
WhatsApp Desktop - WhatsApp, now on your desktop
Messenger Platform - Discovery, chat extensions, and richer experiences
Wafer Messenger - Endless Creativity, Limitless Reach.
Expensive Chat - Chatroom where you pay per letter