I often have to let my sons doodle, play some pre-screened games, play back recordings, view photos, etc. And have been concerned that they could end up on apps that are sensitive such as banking etc or those that sadly contain vain or inappropriate elements as a fearsome robot I encountered on the MalwareBytes antivirus app. I do try to strictly urge them to leave certain apps alone and they seemingly do try adhere. I as well make effort in trying to monitor to try and ensure they adhere. I had to depend on disabling an apps such as Google Play Store but this was not very convenient. I am aware that an Application lock app should do but I could not find one that is free off pitfalls of its own. Yes the one popular AppLock has content that is largely inappropriate on its interface for example.