Package you get contain of 3 items. Two plugins for nopCommerce and solution for Xamarin (.NET Standard 2.0).
Both plugins, Nop.Plugin.Misc.Mobile and Nop.Plugin.Misc.MobileCart need to be compile and installed at nopCommerce store. First plugin is used to exchange data between store and app, second one is used for checkout process.
Xamarin solution in Visual Studio 2019.