This may be covered in other areas of the design (android wrapper) but it would seem to me particularly useful to allow a download (or 10) of videos to allow for study disconnected from the server. A checkout system if you will. One of my favorite OLPC vignettes was the story of parents waiting for their kids to go to sleep so they could get access to the machine. Kinda like that. As simulations are added perhaps the same can happen for them so that this critical third playful learning piece can also make it home.