Parental Controls
Each user should password-protect their device to prevent unauthorized use. Apple, Android, and Amazon users may configure their devices to require a password to make purchases.
In addition to the above referenced password controls, Android, Apple, and Amazon devices provide specific parental controls that allow parents to set additional restrictions, including restrictions on content and in-app purchases.
Please visit the link below corresponding to the device you have to set up your device or your child's device as you see fit:
Apple (App Store) users should visit:
https://support.apple.com/en-us/HT201304
Android (Google Play) users should visit:
https://support.google.com/googleplay/answer/1075738?hl=en
https://support.google.com/googleplay/answer/1075738?hl=en