On April 10th, 2018, Google announced officially the deprecation of its Google Cloud Messaging (GCM) platform and has advised that all users migrate to use Firebase to handle their cloud messaging needs. They have announced that as early as May 29, 2019, that GCM server and client APIs will be removed. They have ensured that existing client SDKs and GCM tokens will continue to work indefinitely and that existing GCM topic subscriptions will automatically send to the new FCM token.
Why is it important?
Google Cloud Messaging (GCM) is Google’s messaging service layer that Android devices use and allows them to actively communicate with Moki when Google Play Services is installed.
Do I need to do something about it?
No, we expect for all currently used Moki applications to be unaffected and not require any updates or changes to continue working as-is. The changes Google will be making will require us to make some small changes to our server-side code, but these are already finalized and deployed on time.
For more information, you can review Google's official announcement: