ios app appearance settings example ( iOS5 or later )

AppDelegate.m

// in (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

    if([[UINavigationBar class] respondsToSelector:@selector(appearance)]) {
        [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"navbar.png"] forBarMetrics:UIBarMetricsDefault];
        NSDictionary *titleTextAttr = [NSDictionary dictionaryWithObjectsAndKeys:
                                       [UIColor colorWithWhite:0.21f alpha:1.f], UITextAttributeTextColor,
                                       [UIColor whiteColor], UITextAttributeTextShadowColor,
                                       nil];
        [[UINavigationBar appearance] setTitleTextAttributes:titleTextAttr];
    }
    if([[UITabBar class] respondsToSelector:@selector(appearance)]) {
        [[UITabBar appearance] setBackgroundImage:[UIImage imageNamed:@"tabbar.png"]];
        [[UITabBar appearance] setSelectionIndicatorImage:[UIImage imageNamed:@"tabbar_item_on.png"]];
        
        UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController;
        UITabBar *tabBar = tabBarController.tabBar;
        UITabBarItem *tabBarItem0 = [tabBar.items objectAtIndex:0];
        UITabBarItem *tabBarItem1 = [tabBar.items objectAtIndex:1];
        UITabBarItem *tabBarItem2 = [tabBar.items objectAtIndex:2];
        
        tabBarItem0.title = @"Item0";
        tabBarItem1.title = @"Item1";
        tabBarItem2.title = @"Item2";
        
        [tabBarItem0 setFinishedSelectedImage:[UIImage imageNamed:@"friends_icon_on.png"] withFinishedUnselectedImage:[UIImage imageNamed:@"friends_icon_off.png"]];
        [tabBarItem1 setFinishedSelectedImage:[UIImage imageNamed:@"home_icon_on.png"] withFinishedUnselectedImage:[UIImage imageNamed:@"home_icon_off.png"]];
        [tabBarItem2 setFinishedSelectedImage:[UIImage imageNamed:@"settings_icon_on.png"] withFinishedUnselectedImage:[UIImage imageNamed:@"settings_icon_off.png"]];
        
        NSDictionary *highlightedTextAttr = [NSDictionary dictionaryWithObjectsAndKeys:
                                       [UIColor colorWithRed:165/255.0 green:10/255.0 blue:6/255.0 alpha:1.0], UITextAttributeTextColor,
                                       [UIColor whiteColor], UITextAttributeTextShadowColor,
                                       nil];
        [[UITabBarItem appearance] setTitleTextAttributes:highlightedTextAttr forState:UIControlStateHighlighted];
    }
    if([[UIBarButtonItem class] respondsToSelector:@selector(appearance)]) {
        [[UIBarButtonItem appearance] setBackgroundImage:
         [[UIImage imageNamed:@"btn.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0.0, 5.0, 0.0, 5.0)] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
        [[UIBarButtonItem appearance] setBackButtonBackgroundImage:
         [[UIImage imageNamed:@"btn_back.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0.0, 13.0, 0.0, 5.0)] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
    }