A XAML Radial Gauge Custom Control for UWP that is partially drawn by the Composition API.
It uses the release version of Composition API, so this requires Requires Visual Studio 2015 update 1 and Windows 10 10586 SDK on your side.
A blog post that explains the code is right here: https://xamlbrewer.wordpress.com/2016/01/23/building-a-custom-uwp-control-with-xaml-and-the-composition-api/.