title: MVVM Cross Approach to Login/Authentication
body: <p>I am just getting into MVVM Cross. I am now tackling how to code the login code in a cross-platform/MVVM Cross way.</p>
  
  <p>My original approach was to use Xamarin.Auth but this component cannot be used in PCL projects which (correct me if I am wrong) means I need to write code for each platform (Android, iOS, Windows Phone). This isn't the MVVM/MVVM Cross way of doing things.</p>
  
  <p>Whats a MVVM Cross way of handling login and authentication? How have you handled user login in the past?</p>