Morph is an easy-to-setup fly-out mobile menu for WordPress. While designed primarily as a mobile menu, it works wonderfully on both desktop and touch devices, and can be set to be shown at specified resolutions only, meaning – if you so wish – it can easily be used as a mobile-only or desktop-only menu.

Demo: http://codecanyon.net/item/morph-customizable-flyout-wordpress-menu/10685700