Superfly is a responsive WordPress menu plugin that generates vertical push/sliding/static navigation, icon toolbar or fullscreen menu on your choice. It can be used as standalone navigation or compliment your main menu.
Touchy is a premium mobile menu and header plugin for WordPress. Designed with smartphones in mind, it is quick, reactive and super comfortable to use. Next to having been tested thoroughly on different mobile devices, Touchy also works great on desktop browsers, so if you wish, you can even use it on a full-blown desktop site.
UberMenu is a user-friendly, highly customizable, responsive mega menu WordPress plugin. It works out of the box with the WordPress menu system, making it simple to get started but powerful enough to create highly customized and creative mega menu configurations.
WP Mega Menu Pro is a premium WordPress plugin, where you can easily add a mega menu to your site. This plugin includes both horizontal as well as vertical mega menu, it is a built in visual mega menu builder plugin with features to display menu as flyout or megamenu type with orientation as vertical or horizontal type. The plugin has 14 pre-defined skins and you can customize your menu bar with multiple customization options creating your own custom skins.
Jumbo is a WordPress menu plugin that you can add to any theme, and it comes with a bit of a unique twist. Next to allowing you to build a bold, memorable and fully responsive full-screen menu, you can also create an optional, secondary drop-down menu.