You guys have to look at the Parentkit app. I've been using it over 6 months now and it solved a lot of our families issues. It is a great parenting tool. It uses Apple's mobile device management system to allow parents to remotely turn on or off third party apps (Facebook, Youtube, Mindcraft), Safari and media like movies/tv shows. What I mean by turn off/on is that it hides the associated icons so the child can't use them. It does not delete or remove the app/movie from the child's device or account. Using the Parentkit control panel on their own apple device, the parent can schedule time periods when their child's app icons will appear so the child can use it. It also uses the child's age to setup default restriction settings which would hide apps/movie/tv content that may be too mature for them. The actual app is installed on the parents own device and only a profile is then installed on the child's device. Setup and schedule changes require both devices to be connected to the internet via a WiFi or cellular signal. This is the ideal setup and if done properly it works awesome.
Thre are some things it doesn't do, but from my support emails with them it's due to Apple's designer restrictions.
1. It does not have a daily use timer.
2. You can't pick and choose which third party apps are controlled. It's all apps or none.
3. There is no password protection that prevents the child from deleting the profile - although the profile is somewhat difficult to find and if it is deleted, the parent is made aware that the profile was deleted.
4. It also removes any folders that you may have created and reorganizes the icons in alphabetical order.
Parentkit is by far the best parental control app out there to help manage how much our kids use their iPads and iPhones. It's not for everyone and I think is best suited for managing devices of children.