So I've got 4 four kids and was the tech director for a school district that was 1:1. We started iPads about 10 years ago but have now transitioned to Chromebooks. In my observations educational games work well with under 12. After about 12 years old social pressure and lack of complexity keep them from enjoying games that are "educational". Over 12 apps suck as Minecraft, Tynker, Scratch become more inline with an older kids interest. But if you DO make educational apps please keep it up. For example Stack the States / Stack the Countries has been a favorite in with all my kids.