Customize Navigation Bar and Back Button

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

//Changing Navigation Bar Background

    UIImage *navBackgroundImage = [UIImage imageNamed:@"navbar_bg"];

    [[UINavigationBar appearance] setBackgroundImage:navBackgroundImage forBarMetrics:UIBarMetricsDefault];



//Customizing the Title Text of Navigation Bar

[[UINavigationBar appearance] setTitleTextAttributes: [NSDictionary dictionaryWithObjectsAndKeys:[UIColor colorWithRed:245.0/255.0 green:245.0/255.0 blue:245.0/255.0 alpha:1.0], UITextAttributeTextColor,[UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.8],UITextAttributeTextShadowColor,[NSValue valueWithUIOffset:UIOffsetMake(0, 1)],UITextAttributeTextShadowOffset,[UIFont fontWithName:@"HelveticaNeue-CondensedBlack" size:21.0],UITextAttributeFont, nil]];


//Customizing the Appearance of UIBarButtonItem

// Change the appearance of back button

    UIImage *backButtonImage = [[UIImage imageNamed:@"button_back"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 13, 0, 6)];

    [[UIBarButtonItem appearance] setBackButtonBackgroundImage:backButtonImage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

    // Change the appearance of other navigation button
    UIImage *barButtonImage = [[UIImage imageNamed:@"button_normal"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 6, 0, 6)];
    [[UIBarButtonItem appearance] setBackgroundImage:barButtonImage forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

return YES;
}

The UIEdgeInsets is structure that specifies float values for each cap inset: top, left, bottom and right areas of an image. For instance, line 1 of the above code instructs iOS that the left 13 pixels and the right 6 pixels of the back button image are not scaled or resized.

Reference