My EventProMobile App file

using System;
using System.Reactive.Linq;
using System.Reactive.Threading.Tasks;
using Akavache;
using EventProApp;
using EventProApp.Helpers;
using EventProApp.Page.Dashboard;
using EventProApp.Page.Login;
using EventProClientApi;
using Microsoft.Azure.Mobile;
using Microsoft.Azure.Mobile.Analytics;
using Microsoft.Azure.Mobile.Crashes;
using ReactiveUI;
using Splat;
using Xamarin.Forms;

namespace EventProMobile
{
    public partial class App : Application
    {
        public static MasterDetailPage MasterDetailPage = new MasterDetailPage();

        public static string AppName
        {
            get { return Constants.ApplicationName; }
        }

        public App()
        {
            LogHelper.LogDebug("At the start of the constructor");
            InitializeComponent();

            MainPage = new NavigationPage(new Xamarin.Forms.Page());

        }

        protected override void OnStart()
        {
            // Handle when your app starts
            MobileCenter.Start(typeof(Analytics), typeof(Crashes));
            BlobCache.ApplicationName = "EventPro";
            MainPage = RunCredentialCheck();
        }

        protected override void OnSleep()
        {
            // Handle when your app sleeps
        }

        protected override void OnResume()
        {
            // Handle when your app resumes
        }

        public static NavigationPage RunCredentialCheck()
        {
            NavigationPage result = null;
            var seq = SecurityHelper.HasUserCredentials()
                                    .ToObservable<bool>()
                          .ObserveOn(RxApp.MainThreadScheduler)
                          .Timeout(TimeSpan.FromSeconds(6))
                            .Select((hasCreds) =>
                            {
                                return (hasCreds) ? new NavigationPage(new RootPage(true)) : new NavigationPage(new StartPage());
                            }).FirstAsync();

            seq.Subscribe((NavigationPage nav) =>
            {
                result = nav;
            }, ex =>
            {
                Logger.Write($"Error:{ex.Message}", Splat.LogLevel.Error);
                throw ex;
            });
            return result;
        }

        public static ILogger Logger
        {
            get
            {
                return Splat.Locator.Current.GetService<ILogger>();
            }
        }

        private static ViewModelLocator _locator;

        public static ViewModelLocator Locator
        {
            get
            {
                return _locator ?? (_locator = new ViewModelLocator());
            }
        }

        public static Xamarin.Forms.Page GetMainPage()
        {
            return new RootPage(true);
        }

        public static Xamarin.Forms.Page GetLoginPage()
        {
            return new Login();
        }

        public static Xamarin.Forms.Page GetSignupPage()
        {
            return new Signup();
        }

        public static Xamarin.Forms.Page GetStartPage()
        {
            return new StartPage();
        }
    }
}