Google requires we show a permanent notification when an app is running the background. On Android 8.0 (Oreo) and higher, you can turn off this notification without affecting other notifications (Family Messenger).
How can I turn off the permanent notification?
Perform the following steps from your child's device.
If you have Prevent Uninstallation enabled, we recommend you temporally turn off protection on your child's device in order to access Boomerang's permissions list.
1. Open Android Settings
2. Tap on Apps (sometimes named Apps & notifications)
3. Tap on Boomerang
4. Tap Notifications
5. Uncheck Important Background Work Notifications
Boomerang will continue to run in the background but no longer show the permanent notification.