Windows Store apps are unique in their appearance and behavior. The emphasis in these applications is on users and the way they interact with your application. You should following the principle of Microsoft design style and available guidance to design your app.
Consider separation of concerns, reusability, and maintainability of your application when planning the logical layers of your solution. Divide your application into three main loosely coupled layers: presentation layer, business layer, and data layer. Wherever you have the requirement to integrate legacy software, consider using WinMD components in your Windows Store app.
Use the MVVM pattern to implement the logical layers of your solution. The MVVM pattern is helpful ...