jQuery.naviDropDown is a simple jQuery plugin which allows you to create a simple drop down menu, utilising hoverIntent, and jQuery's own slideUp and slideDown effects. You can also set the orientation of the drop down depending if your navigation is horizontal (default) or vertical, and set the duration and easing method of both slideUp and slideDown on initiation of this plugin.  

YoxView is a free Lightbox-type media and image viewer jQuery plugin. It's easy to use and feature-rich.   YoxView - Features: FREE to use under the MIT license and open-sourced. Extremely easy to integrate.  Supported content: images, video, inline content, iframes, Flash and more.  On-line Video support - play YouTube/Vimeo/Hulu/etc. Content is resized to fit inside the browser's window. Plugins to display images from Flickr/Picasa and video galleries from YouTube. Skins available to

Slidebars is a jQuery plugin for quickly and easily implementing app-style revealing menus and sidebars into your website. Slidebars is not just for handheld devices, it can be used for implementing revealing content on sites and screens of all sizes.   

Bootbox.js is a small JavaScript library which allows you to create programmatic dialog boxes using Twitter's Bootstrap modals, without having to worry about creating, managing or removing any of the required DOM elements or JS event handlers.  

jQuery.mmenu is a jQuery menu plugin for creating app look-alike, responsive, sliding, off-canvas menus for you mobile and desktop responsive website.   jQuery.mmenu - Features: Fully responsive CSS framework generated with SCSS. Creates sliding panels as easy as menus. Menu can be positioned at the top, right, bottom or left, at the back, front or next to the page. Use sliding horizontal or expanding vertical submenus. Optionally open the menu by dragging the page out of the viewport. P

nanoScroller.js is a jQuery plugin that offers a simplistic way of implementing Mac OS X Lion-styled scrollbars for your website. It uses minimal HTML markup being .nano > .content. The other scrollbar div elements .pane > .slider are added during run time to prevent clutter in templating. The latest version utilizes native scrolling and works with the iPad, iPhone, and some Android Tablets.  

Simple Modal is a small plugin to create modal windows. It can be used to generate alert or confirm messages with few lines of code. Confirm configuration involves the use of callbacks to be applied to affirmative action; it can work in asynchronous mode and retrieve content from external pages or getting the inline content. Simple Modal is not a lightbox although the possibility to hide parts of its layout may partially make it similar.  

Flaunt.js is a jQuery script that allows you to create a responsive, nested navigation out the box. It was built to overcome responsive design challenges which faced a huge percentage of websites. This challenge was to show nested navigation items on click-demand, without the event taking you through to the page you've pressed...  

jPanelMenu is a jQuery plugin that creates a paneled-style menu (like the type seen in the mobile versions of Facebook and Google, as well as in many native iPhone applications).  

jQuery Nested is a jQuery plugin which allows you to create multi-column, dynamic grid layouts. Unlike other libraries and jQuery plugins similar to Nested, this is the first script out there that allows you a complete gap-free layout.