title: Which delegate function is called within a class on tapping the home-button
body: <p>I have a pop-up which has to be hidden when the user moves away from the class. 
  On tapping on the home button, the doesn't happen.</p>
  
  <pre><code>- (void)applicationDidBecomeActive:(UIApplication *)application
  
  - (void)applicationDidEnterBackground:(UIApplication *)application
  </code></pre>
  
  <p>Other than the above functions is there any other delegate functions which would be called in the same class (not the app-delegate class).</p>