Smooch.io for Facebook Messenger - Message your customers from Slack, Front, a bot or anywhere!
DogeHouse - Open-source audio chat on the web.
It's Alive - Create a Facebook bot in minutes
Cozyroom.xyz - A group chat with simple avatars and geo location
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Walkie - Walkie is an online communication providing software that allows you to remain in touch with the other persons.