iOS custom back button category.

UIViewController+JIMBackButton.h

//
//  UIViewController+JIMBackButton.h
//  CupMaster
//
//  Created by Juan Felipe Alvarez Saldarriaga on 11/7/13.
//  Copyright (c) 2013 juan.im. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIViewController (JIMBackButton)

- (void)JIM_setupCustomBackButton;

@end

UIViewController+JIMBackButton.m

//
//  UIViewController+JIMBackButton.m
//  CupMaster
//
//  Created by Juan Felipe Alvarez Saldarriaga on 11/7/13.
//  Copyright (c) 2013 juan.im. All rights reserved.
//

#import "UIViewController+JIMBackButton.h"

@implementation UIViewController (JIMBackButton)

- (void)JIM_setupCustomBackButton
{
    self.navigationItem.hidesBackButton = YES;
    
    if ([self.navigationController.viewControllers count] <= 0) {
        return;
    }
    
    if ([self.navigationController.visibleViewController isEqual:self.navigationController.viewControllers[0]]) {
        return;
    }
    
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"⬅︎" style:UIBarButtonItemStylePlain target:self action:@selector(JIM_customBackButtonPressed:)];
}

- (IBAction)JIM_customBackButtonPressed:(id)sender
{
    [self.navigationController popViewControllerAnimated:YES];
}

@end