This tutorial explains how to easily hide the AppStore icon from the homescreen from your iPhone or iPad, which can be quite useful when you don't want your kids or anyone else to install new apps on our device.
Go to Settings > General. Tap on Restrictions and then on Enable Restrictions. You will be prompted to create a passcode to access the Restrictions section, this passcode is different from the one you normally use to unlock your device.
Toggle off the Installing Apps entry.
Back to your homescreen you will notice that the AppStore icon is no longer available!
Other type of restrictions can also be enabled from this menu:
Deleting apps - Prevent anyone from un-installing apps from your device.
In-App Purchases - Prevent in app purchases (e.g premium content for games, paid subscriptions,..)