From Apple's own Parents' Guide to iTunes
Apple has recently included a section on the App Store called Parents' Guide to iTunes to explain some of the lesser known features available to protect children using iOS devices. Whether they have their own iPods or they borrow your iPad, these precautions are so simple you should consider them a basic setup for any iOS device you own.
1. Apple IDs are the door to your credit card
Whenever you set up a device for the first time, an Apple ID is requested. This will be used for things from iCloud backups to iTunes and App Store purchases. Apple recommends creating specific accounts for children even on shared devices they won't use all the time. By having different accounts, you can select specific restrictions to what's allowed on the device without limiting your own use. These cover things like downloading apps, buying and making in-app purchases, volume limits or web browsing.
2. Use gift cards and iTunes vouchers
Once you have a separate Apple ID account for the child using the iPad, iPhone or iPod Touch, you can skip the billing part selecting "None". This is the best way to avoid unauthorised charges on your credit card. The account can be topped up or recharged with credit in several ways, giving you the option to allow your child to buy content with a limited amount of money.
The system is also prepared to gift certain amounts regularly, like a modern day virtual pocket money or allowance. There's also the option to purchase virtual or physical iTunes gift cards available in most shops and big supermarkets. These make very lazy presents that kids absolutely love. I have bought some scratch cards myself when they have 3 for 2 offers and have experience the thrill of redeeming it.
3. Limiting content with parental controls
The restrictions mentioned on the first point are basic tool to protect children from unsuitable content available on iTunes. You can access these on the device itself, so make sure that the four-digit password is not easy to guess. Some cases of children buying upwards of $1,000 worth of in-app purchase content were found to be disabling the buying restriction after getting this code.
Both iTunes and the App Store are very strict with the available content and how it's sorted. It's definitely worth your time to test different restrictions for films, TV shows and apps depending on their category as well as explicit language on music and podcasts.
4. Ask for your iTunes password with every download
The Restrictions menu also has a handy feature for both young ones and adults: requesting the user to type the iTunes password before every download.
Imagine your boy has asked you to download a game on his iPad mini. Well, since you have to supervise every purchase, you go to the App Store, have a quick look and download it for him using the iTunes password. With the standard settings, the system won't ask you for the password again for another 15 minutes. This means giving anyone access to the iTunes credit or make purchases billable on your credit card without even realising!
5. Using passcodes on your own device
Using a short numerical password on iOS devices can be a great tool for preventing usage without permission. Just like most mobile phones, a four-number passcode is required to access the device every time its turned on. You can access the camera app and there are some obscure faults with this system, but it should work as a basic barrier, especially for your own device.