Microsoft just published a blog post on controlling app access to kids on Windows Phones. In short, you’re going to go through Zune.net and you can block apps and you can also specifically block based on ESRB rating. They note:
But he or she can still download free apps—something worth remembering. (If you want to allow them to buy a specific paid app later, you can always go in and turn this off temporarily.)
There’s more detail on the site but remember that this is a pretty big loophole. There’s are too many free apps that are probably beyond what you want your kids to see on Windows Phones (just check the entertainment category ). Nonetheless, it’s a good start and worth taking note of.