Pusher Beams - Send push notifications programmatically at scale
Snowball Smart Notifications - Get the notifications you want and none of the rest
Push Notification Preview - A simple tool for previewing push notification copy
Engagespot - Engagespot is the easiest way to build your product's multi-channel notification infrastructure. Deliver In-App, Email, Push, SMS, WhatsApp and chat notifications from your app to your users with a single API.
Ultimate Push Notifications by Ecomfit - Retarget customers and protect abandoned cart to boost sale
Ropig - More signal, less noise.