After setting up the app portion of Boomerang Parental Control on your child's iOS device, we will require the installation of a Device Profile for screen time and app controls. 

Tips / Troubleshooting 

1. When opening the Boomerang Parental Control app after the Device Profile installation, it may show an error and to try later. We recommend you swipe close Boomerang Parental Control and reopen it. This usually clears this error and allows Boomerang Parental Control to refresh itself successfully.
2. All commands sent to time out, extend time, block apps by age group or the daily automated screen time schedule require that your child's device has an active internet connection (wi-fi or cellular). If the device is offline, the changes will not work. 
3. You can have only one profile ready to install at a time. For example, if you download a profile and don't install it, and then download a second profile, only the second profile is available to be installed. If a profile is not installed within 8 minutes of downloading it, it is automatically deleted.
4. We cannot prevent deletion of the Device Profile. If your child does remove it, we will inform them that their parent has been notified about the removal. We inform parents via an email (your group email) and via any parent device that has Boomerang Parental Control installed in Parent Mode.  In order to reinstall the Device Profile, make sure the Boomerang Parental Control app is swiped out of the recent apps list and reopen it. It will then prompt you to reinstall the Device Profile. Follow the same steps above. 

From Apple Support: https://support.apple.com/en-us/HT209435