What are some alternatives?
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
deployd - API development tool for Web and Mobile developers.
CloudBoost.io - One Complete Database Service that does data-storage, search,real-time and a whole lot more.
GUN - Self-hosted Firebase.
Backand - Backand is a backend-as-a-service for AngularJS that provides out-of-the-box social login, push notifications, Ionic integration and more.
Nakama - Nakama is an open-source distributed social and realtime server for games and apps.