In AppDelegate delete explicit @synthesize.
Add storyboard and use it to instantiate navigation controller and FailedBanksListViewController.
In FailedBankDetailViewController.m delete unnecessary @synthesize.
In FailedBankDetailViewController.h IBOutlets change strong to weak. In .m delete method dealloc.
In storyboard add segue to FailedBankDetailViewController. Copy view layout from .xib to storyboard and delete .xib.