On GitHub Microsoft have published a lot of examples for Universal Apps: the link is https://github.com/Microsoft/Windows-universal-samples
This repo contains the samples that demonstrate the API usage patterns for the Universal Windows Platform (UWP) in the Windows Software Development Kit (SDK) for Windows 10. These code samples were created with the Universal Windows templates available in Visual Studio, and are designed to run on desktop, mobile, and future devices that support the Universal Windows Platform.
Universal Windows Platform development
These samples require Visual Studio 2015 and the Windows Software Development Kit (SDK) for Windows 10 to build, test, and deploy your Universal Windows apps.
Additionally, to stay on top of the latest updates to Windows and the development tools, become a Windows Insider by joining the Windows Insider Program.
Using the samples
The easiest way to use these samples without using Git is to download the zip file containing the current version (using the link below or by clicking the “Download ZIP” button on the repo page). You can then unzip the samples and use them in Visual Studio 2015.
The samples use Linked files in Visual Studio to reduce duplication of common files, including sample template files and image assets. These common files are stored in the SharedContent folder at the root of the repository and referred to in the project files using links.
For more info about the programming models, platforms, languages, and APIs demonstrated in these samples, please refer to the guidance, tutorials, and reference topics provided in the Windows 10 documentation available in the Windows Developer Center. These samples are provided as-is in order to indicate or demonstrate the functionality of the programming models and feature APIs for Windows.