Microsoft has finally released Windows 8, and is promoting its launch with a billion-dollar marketing campaign. This creates new opportunities for app developers, especially since the Windows Store isn’t yet as crowded as the Apple and Android counterparts. However, before you go ahead and start programming an app, I’d suggest you design some quick prototypes first to validate your idea. Play with different variants, show them to your peers, and adapt the designs based on the feedback you receive. Although …