My ds1 also only gets short moments with the iPad or iPhone as a distraction. I have heard people comment on the sly and have even had face to face comments such as "oh my. He is better on that thing then me."
Funny thing is at first I just Downloaded things with sounds and bright colours as a distraction. I never taught him to play angry birds or any other apps I have since downloaded for him. He teaches himself. (might I add he plays learning games that involve memory, spelling and other educational qualities). He is 2.5yo and I'm proud of how smart he is . He still loves the outdoors and helping with things just as any other child does so all I can gather from this is that it's enhancing his intellect as a child and there is nothing wrong with it .