MvxTabbedPage ViewModel with navigation for all child tabs

HomeViewModel.cs

public class HomeViewModel : MvxViewModel
{
    private readonly IMvxNavigationService _navigationService;
    private bool _firstTime = true;
    private IMvxViewModel _previousViewModel;

    public HomeViewModel(IMvxNavigationService navigationService)
    {
        _navigationService = navigationService;
    }

    private Task ShowInitialViewModels()
    {
        var tasks = new List<Task>
        {
            _navigationService.Navigate<DetailsViewModel>(),
            _navigationService.Navigate<SecondDetailsViewModel>(),
            _navigationService.Navigate<ThirdDetailsViewModel>()
        };
        return Task.WhenAll(tasks);
    }

    public override void ViewAppearing()
    {
        if (_firstTime)
        {
            ShowInitialViewModels();
            _firstTime = false;
        }
    }
}