As was raised by @AdvKern in #5, none of the Android samples currently work. I've found two issues using the latest stable Visual Studio 2017 and Xamarin.Android tooling:

1. NuGet packages which are targeted using the new .csproj PackageReference format will not get deployed to the device. A solution would be to revert back to using packages.config.

2. Invoking unmanaged code raises InvalidProgramException with message "Invalid IL code". This seems to be appeared after Xamarin Mono 5.0 update which introduced Roslyn compiler. Reason unknown. Going to test latest preview tooling to see if it makes any difference.