Cloud Messaging - FirePush

Firebase Cloud Messaging (FCM), formerly known as Google Cloud Messaging (GCM), is a cross-platform cloud solution for messages and notifications for Android, iOS, and web applications, which currently can be used at no cost.

The service is provided by Firebase, a subsidiary of Google. On October 21, 2014, Firebase announced it had been acquired by Google for an undisclosed amount. The official Google Cloud Messaging website points to Firebase Cloud Messaging (FCM) as the new version of GCM.

It is a tool for sending directly your messages by FCM.