For example, with Notepad++ you can right click a file and you see an "Edit with Notepad++" item. Because these context menus items are added via registry (and the MSIX container-izes it), the OS is...
Hi brasmusson
If your app is under active development, you can add a context menu entry for your app via a File Type Association and verb registration in your AppxManifest.xml (or package.appxmanifest if you're using the Visual Studio packaging project). Have a look at this example for more details - Modernize existing desktop apps using Desktop Bridge | Microsoft Docs
Cheers,
Tanaka