Apps and online games offer so many possibilities nowadays that not setting any restrictions for your children is not an option. It is important to explain to your children why you restricted the use of apps on their tablet or smartphone and to allow exceptions when they need it. Reasonable rules are also easier to accept for children and to enforce for you. Continue to check their use as they get older, but give them increasingly more freedom within certain limits. This teaches them to use their devices responsibly.
Restrict in-app purchases completely or give your child a fixed budget he/she can spend on apps or music. Never give a child access to your credit card or financial information.
Set restrictions in the App Store
Set restrictions in the Play Store