What are some alternatives to OneSignal and Pusher Mobile Push Notifications API?
Free unlimited cross platform push notifications! iOS, Android, Windows Phone, Phonegap, Unity, Marmalade, Adobe Air - we support them all! Easy integration, open-source SDK.
Firebase is a cloud service designed to power real-time, collaborative applications. Simply add the Firebase library to your application to gain access to a shared data structure; any changes you make to that data are automatically synchronized with the Firebase cloud and with other clients within milliseconds.
Pusher is the category leader in delightful APIs for app developers building communication and collaboration features.
It is a cross-platform messaging solution that lets you reliably deliver messages at no cost. You can notify a client app that new email or other data is available to sync. You can send notification messages to drive user re-engagement and retention. For use cases such as instant messaging, a message can transfer a payload of up to 4KB to a client app.
Twilio offers developers a powerful API for phone services to make and receive phone calls, and send and receive text messages. Their product allows programmers to more easily integrate various communication methods into their software and programs.