Pusher Beams - Send push notifications programmatically at scale
SendBird - SendBird is messaging-as-a-service.
Truepush - Unleash limitless possibilities with Truepush and save up to $600 monthly. Free up to 10K Subscribers on all features.
Chat by Stream - Build and ship in app messaging in a few hours
PushOwl - Re-engage website visitors with push notifications
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.