title: Calling UIViewController method from app delegate
body: <p>I know there are duplicates of this question but my situation is different here.</p>
  
  <p>When user goes back to the home <code>(void)applicationDidEnterBackground</code> gets invoked from the <code>AppDelegate</code> class. However once user presses home button, I don't want user to see this view controller again, so I have a method named <code>(void)goToBeginning</code> that switches to another view controller. I want to be able to call this method from AppDelegate. I don't really want to use <code>NotificationCenter</code> for this. Also the picked solution here:
  <a href="https://stackoverflow.com/questions/8141332/calling-view-controller-method-from-app-delegate">Calling view controller method from app delegate</a>
  does not work for me as it initialises new object whereas I want to be able to call an object that is already in the view. How can I do that? I am using iOS 7 and XCode 5.</p>