Math Rounds is a 2D HTML5 (and JavaScript) that intends to promote interest in math (and leading up to computer science) in children. It utilizes localstorage for game saves (hey, at least it's more reliable than cookies!). The mobile ports are built through the Intel XDK for iOS, Android, and Windows Phone (not only games coming to the Windows Store but educational ones). Outside of the XDK, the app was also ported to a chrome app (not extension) including a custom icon on Chrome OS devices.
For more information (description, pre-release screenshots, etc.), check out the ChallengePost - http://challengepost.com/software/math-rounds