We just download a few videos of our daughter's favourite show and put them on the memory card for her to watch. Or put some of her favourite music for her to listen too. If you have an unlimited data plan, there is a youtube app so you could watch youtube videos (there's plenty of classic disney cartoons on there for example), but if you don't have an unlimited data package downloading over the air is going to be very expensive.
Baby Go! is an awesome app, but geared more towards toddlers.