SendBird - SendBird is messaging-as-a-service.
Managed MongoDB by DigitalOcean - Dedicated MongoDB starting at $15/mo
Chat by Stream - Build and ship in app messaging in a few hours
DigitalOcean App Platform - A reimagined PaaS (Platform as a Service) for all your apps
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Chatroll - Chatroll is the leading provider of interactive tools for social publishers.