Smooch.io for Facebook Messenger - Message your customers from Slack, Front, a bot or anywhere!
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
It's Alive - Create a Facebook bot in minutes
Chatlio - When you have a business to run, your average instant messaging software just will not do. You need an internal presence upon which your entire team can collaborate on. Read more about Chatlio.
Avochato - Text messaging for your business.
Sparkcentral - Good old fashioned customer service, delivered in a high tech way