From BETT this year, there were very little development buzz for android. Version usage was one of the most common issues raised. Android users just don't update, so this means a headache for developers. iOS and Apple are more expensive, but they've been in the educational market for a few years now, and this will only grow. It was hoped that windows surface might have been a real competition, but they've had to slash educational pricing for the rt version, and the Pro is a joke in terms of cost, so I can't see developers spending the time on this platform.