OneSignal
OneSignal

Android – Implement Onesignal (Alternative for firebase)

Onesignal is one of the best alternative for firebase push notification. It is easy to use, free for push notification, however it has 30K limit for subscribers. Onesignal almost support all kind of operating systems.It has 860K+ users, who are currenlty using onesignal. For more you can visit its official site.