AT&T iPhone Parental Controls
It depends what you want.
If you simply want to block apps, websites, and have (a little) control over data use, iPhone restrictions may be all you need.
By going into Settings &gt; General &gt; Restrictions &gt; Websites, you can choose which sites you’d like to block from the phone. This works over both WiFi and Cellular.
You can also disable the App Store to prevent downloading of apps, or set an age limit on the apps downloaded.
Another thing you can do is configure your Cellular Data settings then lock the pane by selecting Don’t Allow Changes in Restrictions &gt; Cellular Data Use
The main thing that AT&amp;T parental controls would be good for is controlling what happens on your mobile data. In iOS controls, you cannot restrict phone numbers called, though AT&amp;T can. Also, the AT&amp;T app allows you to restrict cellular use during certain times of the day.
In conclusion:
Choose iOS restrictions if you want control over their activities on WiFi AND Cellular. Also choose this if you want to restrict app downloads. (free)
Choose SmartLimits if you want to have more control over your children’s activities over cellular. This is not limited to data, but also includes calls and texts. ($4.99/mo one line, $9.99/mo up to ten lines)