I've ported the Sphero Ball Control to Windows Store
However, because Windows Store apps can't access a very full Bluetooth stack, then I had to use a desktop element (a Windows Service) to make the code work.
This means that the app can not currently be submitted to the Windows Store.
If you want to see Sphero in the Windows Store, please write to Microsoft and comment and vote on this thread/issue now:
Here was the demo