A classic analog clock realized entirely with BoxView.
If you open the solution in Xamarin Studio, it will not be able to load the Windows Phone project; and if you open the solution in Xamarin Studio under Windows, it will not be able to load the iOS project either.
Xamarin.Forms doesn't yet have a vector graphics programming interface, but it does have a BoxView. Although normally used for displaying rectangular blocks of color, BoxView can be sized, positioned, and rotated. This is enough to render a classic analog clock.
Charles Petzold