Chatfuel - Chatfuel is the best bot platform for creating an AI chatbot on Facebook.

Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.

Botsify - Ever wonder if you could replace your live chat support system with a chatbot?. Its possible now with Botsify Chatbot For Website.

Keybase Chat - End-to-end encrypted chat built into Keybase

ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.

Crypho - End-to-end-encrypted messaging and file sharing