Please recommend great ipad app for 3year old?

My son is 3 and there are so many Ipad apps out there I don't know what to get him. His mother tongue is french but he understands english, so I would like an app that speaks english to develop his language skills,so not just a simple game. I already have alphabet apps, so anything with some english in it, fun, even a game but it needs to "speak" english, maybe a few story books as well... thanks