Xamarin has today released a preview for WatchKit support in Xamarin Studio, enabling developers to create and test new Apple Watch apps directly inside the software package. The WatchKit Preview is now available for download from the Xamarin developer website, according to the company:
We've added new templates for Watch apps and Watch extensions inside Xamarin Studio. Start with a new or existing iOS app, add a Watch App to house your interface, and then add a Watch extension to power the interaction. Xamarin Studio does all of the heavy lifting for you.
It's also possible to test apps in both Glance and Notifications mode from the command line too, which is handy for ensuring everything works as it should. Be sure to check out the WatchKit Preview guide for more details, including steps on how to build UIs since the team have yet to include designer support.
Do note that this is a preview release and is by no means considered stable.