DGS3 has been using the iPad since he was about 1 1/2. He is super smart and has learned a lot on the iPad and watching the Disney Jr channel (and some Nick, but I didn't do that!) He is already past where he would be when he gets out of pre-k (which he won't start until later this year), according to several pre-k and kindergarten teachers that are friends. The apps he has are the Disney Jr apps, Umizoomi apps, Dora and Diego apps, etc. They have counting, shapes, alphabet recognition, etc.
We were talking earlier today that we need a video camera on him 24 hours a day to record what comes out of his mouth. He likes to be the teacher and teach us things so we have to act dumb sometimes so he can teach us stuff like how many sides does an octagon have.