The iPhone/iPad App Store has a section devoted to special education. I was able to find some announcements from the end of October, so it's quite new.
There's a lot there, from sign language to communication to accessible readers to language development apps.
This opportunity to market and sell focused special needs apps could be a very big development. I'm excited, I've written before about our own experiences with my son's iPhone, including the weaknesses in iPhone parental controls. He's probably moved beyond most of these offerings, but we'll be examining them in more depth. (Lately he's been using the money to earn to buy games, which is an improvement on using it to buy candy.)