Pusher Beams - Send push notifications programmatically at scale
Notif.me SDK - A Node.js lib to send all your transactional notifications
Ultimate Push Notifications by Ecomfit - Retarget customers and protect abandoned cart to boost sale
Clank - Explore the biggest crypto transactions across blockchains
PushNinja - by 500apps
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.