I had the fortune to be involved developing the LEGO Mindstorms EV3 programming software. Under the hood, it was a small web browser shell (using Mono on Mac and WPF on Windows) around a Silverlight Out-of-Browser app. Anything beyond the permissions of the Silverlight app (e.g. bluetooth/USB comms) was an RPC from Silverlight to the shell.
After completing the Mac/Windows app, LEGO wanted to deliver a similar experience on iPad. There was no Silverlight there, and it was clear there never would be. But we were able to leverage Xamarin stuff to reuse most of the same codebase, just with an iOS UI on top.