RTCleanNavigationBar

UINavigationBar subclass that removes the shadow image while retaining translucency effect in iOS 7 and up

Usage

You need to initialize the UINavigationController to use this subclass, like this:

UIViewController *vc = ...;
UINavigationController *nc = [[UINavigationController alloc] 
	initWithNavigationBarClass:[RTCleanNavigationBar class] 
	toolbarClass:nil];
[nc setViewControllers:@[vc]];
...

In order for the bar to seamlessly blend with the view controller contents, set its barTintColor to the VC's background.

[[UINavigationBar appearance] setBarTintColor:[UIColor whateverColor]];