If, while setting up the child app, you get an error verifying installation, it's usually because the device already has a mobile device management profile installed on it.
To check, open the Settings app on the Home Screen of the device and go to Settings->General->Device Management (or Profiles and Device Management).
Click on that and look for something that says MOBILE DEVICE MANAGEMENT.
You'll need to remove that to continue the setup.
To check, open the Settings app on the Home Screen of the device and go to Settings->General->Device Management (or Profiles and Device Management).
Click on that and look for something that says MOBILE DEVICE MANAGEMENT.
You'll need to remove that to continue the setup.