At Build 2014 the world was introduced to the idea of creating Universal Windows apps. This technology will allow developers to extend platform commonality across multiple Windows devices from one shared project. In this session I will demonstrate what you will need to know to get going quickly on building one application for both Windows Phone 8.1 and Windows 8.1 OS. We will also see how to extend your project to include other new features. This talk was given at ConFoo 2015.