The HMT is fundamentally an Android 8.1 device. It runs standard Android applications, built using standard Android development tools.
Since Xamarin generates native Android applications they can be developed, installed and run on the HMT just like any other application – using the development environment you are used to.
Using embedded WearML in Xamarin will differ slightly from native Android in that directives should be placed in the AutomationProperties.Name field. When the application is compiled for Android, this property will set the android:contentDescription field for the corresponding element. To learn more about using directives, see the WearML Embedded API.
For more information on developing application using Xamarin for the HMT, follow the instructions for the Android Framework.