Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Smooch.io for Facebook Messenger - Message your customers from Slack, Front, a bot or anywhere!
LiveChat - LiveChat - premium live chat software. Approach customers directly on the website, make connections and drive more sales using LiveChat.
It's Alive - Create a Facebook bot in minutes
HelpScout - Help Scout is a simple, straightforward way to provide excellent support
Drift - A messaging app that helps you grow your business.