Mobile App (Xamarin Forms) iOS/Android

I need to demo app with Xamarin and .NET STANDART 2.0 The app contains 3 screens: 1 - Authentication screen with a checkbox and sign in button. 2 - Loading screen. 3 - Screen of the authenticated area with sign out button and checkbox button for allways show login screen (the value os this checkbox is inverted value of first screen checkbox). This app will only authenticate itself in Google OAuth requesting the user's permission, after the user allows the authentication of the App, the authenticated user will go to a screen that show email and token of authenticated user and contains sign out button and a checkbox. If the button is checked from the first screen always when the application opens it will go to authenticated screen (screen 3). I need all source code working in Visual Studio 2017 Community (with no errors)