OneSignal is a high volume push notification service for websites and mobile applications. OneSignal supports all major native and mobile platforms by providing dedicated SDKs for each platform, a RESTful server API, and a dashboard.
We’ve built the smartest, most aware, precise, easy-to-use, scalable, secure and powerful push messaging platform on the planet. Our Push messaging platform leverages all that is unique about mobile as a channel, and that lights the spark to create meaningful and valuable mobile experiences. We help put your app in front of your users at the right time, and in the right place to drive usage and brand engagement.
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.
With Parse, you can add a scalable and powerful backend in minutes and launch a full-featured app in record time without ever worrying about server management. We offer push notifications, social integration, data storage, and the ability to add rich custom logic to your app’s backend with Cloud Code.
Apple Push Notification Service
It is the centerpiece of the remote notifications feature. It is a robust, secure, and highly efficient service for app developers to propagate information to iOS (and, indirectly, watchOS), tvOS, and macOS devices.