Mobilize adds a lightweight mobile menu to your site, if the width is lower than a certain value.

A responsive mobile menu for your WordPress site.

A plugin that allows you to create and customize slide-in sidebars which you can populate with widgets.

Add a native-style, off-canvas, responsive mobile navigation menu to your site.

Add off-canvas sidebars (Slidebars) containing widgets, menus or other content using the Slidebars jQuery plugin.