Tapyble

This is the only app that you are going to need in order to control you kid's device use. It is easy to set up and you only need less than a minute to have a profile ready.
This app creates a timer for each activity. After the time of the specific activity over, the app displays a message. This specific message can only be removed with a pass-code.
Further, this app supports multiple profiles which means that it can be modified for several kids, if needed.
Here are the main features of the app:
- Prevent children from using device when the play time is over
- Ability to quickly monitor the usage of the app every day
- Set up multiple profiles for one or more children
- Quickly and easy monitor the device use per day
- Protect timer from being disabled by setting a passcode
- Easily add your own messages and custom sounds
Give this app a try and see for yourself how easily you can monitor and control the usage of your children’s devices.

Note: KidTime is not able and neither any other app to lock out your children of the apps and device they are using. This because it is against Apple's usage policy and therfore not allowed by any of the iOS devices.