I started this over in the Droid forum as thought it might be a generic Droid issue, turns out that a new Droid app works fine, but a new X.Forms app on Droid does not.
I created a brand new X.Formed Shared Library solution containing iOS and Droid. Compile and run as iOS, works fine. Compile and run as Droid, it starts the app but appears to hang with the app title along the top. Eventually the OS tells me it has stopped responding.
Any suggestions on getting past this? I can place a breakpoint in the default GetMainPage() method and it runs the code, it just doesn't render anything on screen.