MVVM with IOS and Namespace Issues

Hi All,

I feel that this is pretty easy but I am missing something to connect the dots. I am creating an app that reads a file on the local device. From what I see,
I need to create this utility class in the IOS folder to use Xamarin.IOS File classes and etc... My view model then consumes this utility class which resides i the IOS namespace along with the view.

It looks like the App class indicates which form to navigate to first. My question is, how can I tell the app class to navigate to this form when it lives in the IOS? I am having trouble understanding how the dependency lives between the the different namespaces.

Should everything live in the main namespace?

Thanks!