Kids learning English

I downloaded a few apps for my niece, for learning English. I've never searched for these kind of apps before, and I'm surprised that how many there are in the app store. Hmm, if there were so many good apps when I grew up, how easy it would be for me to learn English! Well, while there are many apps out there for learning purposes, there are also many out there that get kids addicted, like games and cartoons. It's important that parents have some control over the use of the devices, so that kids knows they can or can't use them.