This has happened quite a few times.
Application working fine. Then I chose a wrong delegate for a view Application did not work (expected) So I chose the right delegate for the view Application still not work / load (should have worked though) Quiting Xcode and returning still doesn't fix it. Only thing to do is delete the project and recreate it
Anyone faced the same problem, any clues on how to fix it ?
I figured out what was wrong.
When I assigned Files Owner as the delegate to UINavigationItem the "AppDeleagate" stopped pointing to the Files Owner. When I reset the AppDeledate delegate to be Files Owner, it worked fine.
This link helped me figure it out. http://forums.macrumors.com/showthread.php?t=377383
Thank you all, for your help :)