title: Can you have more than one subclass of UnityAppController?
body: <p>I need to add some code to <code>application:didFinishLaunchingWithOptions:</code> in <code>UnityAppController</code> that configures Google AdWords Conversion Tracking using their Objective-C SDK.</p>
  
  <p>Editing this file manually each time Unity generates the Xcode project seems error prone, so I'm thinking about adding a post build step using the <code>PostProcessBuild</code> attribute that would apply a patch for generated Unity code. </p>
  
  <p>However, patch files are hard to maintain so I'm looking for alternative solutions. It seems that subclassing<code>UnityAppController</code> via the <code>IMPL_APP_CONTROLLER_SUBCLASS</code> macro and overriding <code>application:didFinishLaunchingWithOptions:</code> there can be one of them. </p>
  
  <p>But after I do this another third party plugin (Google Play Games) that also subclasses <code>UnityAppController</code> using the same method stops working because its app controller is no longer called. Here is a relevant piece of code from that plugin:</p>
  
  <pre><code>@interface GPGSAppController : UnityAppController {
  }
  
  @end
  
  IMPL_APP_CONTROLLER_SUBCLASS(GPGSAppController)
  </code></pre>
  
  <p>So I was wondering if it's possible to subclass the Unity app controller from multiple places. I could not find any documentation for <code>IMPL_APP_CONTROLLER_SUBCLASS</code> online.</p>
  
  <p>Or maybe there is a better approach for adding custom initialization code in Unity on iOS?</p>