Ayzıt
3D Model Viewer and Converter
...Built as a practical utility for 3D graphics creation and programming, Ayzıt is released under the MIT license and is completely free for both commercial and non-commercial use.
For the curious, the main technologies behind it:
C++, Visual Studio, Windows API, WinUI, Direct2D, Direct3D, HLSL, Assimp, and FreeImage.