If you let your kids use an iPhone or iPad, or they've got their own, it's a good idea to make sure they're only installing content that is appropriate for their age. Every iPhone and iPad comes with the ability to enable restrictions on what apps can be deleted or installed. Unless they know the restrictions passcode, they'll have to ask permission to install apps from the App Store, and to delete existing ones.
How to keep your kids from being able to install or delete apps without your permission
Launch the Settings app on the iPhone or iPad you'd like to enable restrictions on.
Tap on General.
Tap on Restrictions.
Tap on Enable Restrictions if they aren't already. If they are, skip to step 6.
Choose a password that only you will know.
Toggle Off the options for Installing Apps and Deleting Apps under the Allow section.
That's all there is to it. You can close out the Settings app and hand over the iPhone or iPad. The App Store icon will completely disappear from their Home screen and the little X you tap to delete apps will not be present either. When you want to install or delete an app, just temporarily disable restrictions, but be sure to re-enable them again after you've installed or deleted what you needed to.