MvvmNavigationToolkit
Navigation toolkit for Windows Phone & Windows Store apps
It's all about wiring VM together with Views using fluent syntax:
_navigationBuilder
.RegisterViewModel<FrameViewModel>().StaticResource().WithoutView()
.RegisterViewModel<MainViewModel>().Singleton().ForView<MainPage>()
.RegisterViewModel<NotesViewModel>().StaticResource().ForView<NotesView>()
.RegisterViewModel<NoteViewModel>().ForView<NoteView>()
.RegisterViewModel<AppSettingsViewModel>().ForView<AppSettingsView>()
;
And now in any ViewModel you can open one in this way:
ServiceLocator.Resolve<NotesViewModel>().Show();