Siouxland Modern Media committee setup a page on 4 steps to secure your phone, which is helpful to ensure your Apple or Android phones are protected.
Qustodio also has a Q & A Webpage with some good questions and answers with regards to using its app on your Android device.
When you put parental controls on an Android device, you can restrict what content can be downloaded or purchased from Google Play on that device based on maturity level. However, purchase approval settings will only apply to purchases made through Google Play’s billing system. The information for this can be found in this page.