SendBird - SendBird is messaging-as-a-service.
Pusher Beams - Send push notifications programmatically at scale
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
PushOwl - Re-engage website visitors with push notifications
Live800 - Live800 is an enterprise-grade Live Chat and Customer Service platform that enables businesses to provide instant support to their customers through a variety of channels, including Live Chat, Email, Phone, and Social Media.
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.