Even after integrating FCM with Tapjoy, you can use other FCM Receivers developed by yourself or third-party services. In this case, just make sure that Tapjoy FCM Receiver is registered before other FCM Receivers in your AndroidManifest.
Tapjoy’s FCMReceiver will only process messages sent from the Tapjoy Dashboard, and messages sent from Tapjoy will not interact with other FCM Receivers.
If necessary, It is also possible to use multiple FCM Sender IDs. When you’re registering multiple Sender ID’s, separate them by commas (,) as shown below:
For iOS, push notifications are processed by the OS, so you will have no problem using your own Push Server or third-party tool in conjunction with Tapjoy Push Notification.