UWP stands for "Universal Windows Platform", meaning Windows 10 apps platform.
This is evolved version of WinRT from Windows 8.x.
While Windows 8.x was very "rigid" in GUI requirements and templates
Windows 10 projects in Visual Studio come completely empty.
A bit too much of "freedom" for even basic apps.
As a solution there are open source sample projects.
One of them is by described in this article:
Modern Apps - Exploring the UWP Community Toolkit @ MSDN Magazine, 2017/01
GitHub - Microsoft/UWPCommunityToolkit: The UWP Community Toolkit is a collection of helper functions, custom controls, and app services. It simplifies and demonstrates common developer tasks building UWP apps for Windows 10. The toolkit is part of the .NET Foundation.
finished app in windows store:
C++ - Introducing C++/WinRT @ MSDN Magazine
"C++/WinRT is a standard C++ language projection for WinRT implemented entirely in header files—the best kind of C++ library. It’s designed to support the authoring and consumption of WinRT APIs using any standards-compliant C++ compiler. C++/WinRT finally provides C++ developers with first-class access to the modern Windows API."