Keep track of "Screen Time" for your children.
ScreenTime is a simple minute-timer app that will create independent timers for each person that you are tracking screen time for. You will receive a notification when their time is up.
You may create "Activities" that allow your charges to earn extra screen time: Reading, exercise, cleaning, etc. These activities may result in a multiplier (e.g. 30 minutes of exercise times 2 equals 60 minutes of screen time), or in a fixed additional amount of screen time (e.g. clearing the dinner table equals 20 minutes of screen time).
A separate schedule for weekdays and weekends to allow a little extra time when school is out.
And of course, everything is editable. If you want to add time or subtract time from the banked amount, its only a tap away.
ScreenTime allows you to share timers among multiple phones and accounts. This is especially useful if there are multiple people keeping track of screen time in your household!