Dialogflow - Conversational UX Platform. (ex API.ai)
CoverMe - Private texting, calling, vault
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Facebook Messenger Kids - Safer and More Fun Video Calls and Messaging
Botpress - Open-source platform for developers to build high-quality digital assistants
Expensive Chat - Chatroom where you pay per letter