Debugging to find which property of the UINavigationBar to change the title of the back button text on the top nav bar. Refer context: http://stackoverflow.com/questions/7237826/how-to-change-uinavigationbar-back-button-text/15018046#15018046

uinavigationbar-uibarbuttonitem

- (void)viewWillAppear:(BOOL)animated
{
    self.navigationItem.backBarButtonItem.title = @"foo";
    self.navigationItem.leftBarButtonItem.title = @"fii";
    [self.navigationController.navigationBar.items enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        UINavigationItem *item = (UINavigationItem *) obj;
        NSLog(@" item: %@", item.title);

    }];
    
    NSLog(@"bar back item: %@", self.navigationController.navigationBar.backItem.title);
    NSLog(@"bar top item: %@", self.navigationController.navigationBar.topItem.title);
    
    
    NSLog(@" back button %@", self.navigationItem.backBarButtonItem.title);
    NSLog(@" left button %@", self.navigationItem.leftBarButtonItem.title);
    NSLog(@" navigationItem %@", self.navigationItem.title);
    NSLog(@" self.title %@", self.title);
}