ANDROID APP TO LIMIT SOCIAL MEDIA TIME ON PHONE

I need an app that will limit the amount of time that a child can use for social media on the phone. The app should not be uninstallable without a password. If the parent decides that one hour a day is what is allowed, once that time is used up, social media sites will be blocked. parent can also set specific allowed periods, such as 4pm to 5pm on mondays, 6pm to 8 pm on tuesdays etc. There should be a trial version and a full version. trial version works for one week, full version permanently Budget $250 NO BIDS FROM INDIAPAKISTAN PLEASE