Apple has a great way to help families keep track of what their children are downloading on their ios devices. Your kids can even have their own profiles. It allows for families to share the apps they have downloaded without having to purchase multiple copies. It lets the administrator see what apps the other accounts have downloaded. Best of all, though, it lets you set requirements for young users to ask permission before an app can be downloaded. If you have specific requirements and standards for the apps you want your kids to use, this feature will help you keep those standards in tact.
The video below is a simple walkthrough on my Macbook of how to set up your iCloud FamilyShare settings. I will add one new child account and even give some information about why you may want to use this feature.