title: What are requirements on "Facebook Login integration" for successful submission to App Center?
body: <p>I'm struggling to submit an Android/iOS application to App Center, however I'm getting constantly rejected with the following reason:</p>
  
  <blockquote>
    <p><strong>General Feedback:</strong></p>
    
    <ul>
    <li>Your Android app does not appear to have Facebook Login integration. Please either implement Facebook Login or remove this  integration as a listed platform in the developer app. See more  details here</li>
    <li>Your iOS app does not appear to have Facebook Login integration. Please either implement Facebook Login or remove this integration as a listed platform in the developer app. See more details here</li>
    </ul>
  </blockquote>
  
  <p>Facebook login button is placed in Settings dialog, where a normal email/password login is located as well.</p>
  
  <p>Unfortunately the review team doesn't specify why exactly it appears to them that Facebook Login integration is missing.</p>
  
  <p>So, are there any specific requirements on Login implementation which I may be missing?</p>