title: Getting the current active UIWindow/appDelegate object without holding the apps objects
body: <p>I'm writing a "blackbox" library. In this library I need to add a subView to any app which uses my library.<br> 
  Therefore, I don't have any reference to the appDelegate nor to the UIWindow of the application.<br> 
  The only thing the external app is doing now is the following : <br></p>
  
  <pre><code>myRec = [[Rec alloc] init];
  myRec.delegate = self;
  [myRec start];
  </code></pre>
  
  <p>where Rec is the blackbox library and myRec is the instance that's used by an external app.<BR>
  Of course, I can't get any reference to the view of the app through the delegate member cause it's not defined like the specific type of the external app. 
  <br><br>
  Any ideas on how to get a grasp on the UIWindow object / appDelegate object <strong>without knowing</strong> their identity in advance ??<br><br> <strong>Thanks !!</strong></p>