I'm very liberal about screen time amount, as long as the kids keep to every other bit of their routine and responsibilities. Eg--after school/after school sport, it's snack then homework then bath and then screen time until dinner, then after dinner if they want until bedtime. On weekends we keep relatively active, but just like adults who want to do what we like with our free time, I try to make sure my kids can do the same. If that means playing football in garden or playing on their tablet, then so be it. If it helps, I use the app called Kidslox which helps me limit on those days where it seems like they're on too much. It basically freezes the tablet so it cannot be used, if I flip the 'switch' on the app so to speak.