jQuery responsiveText is a jQuery plugin to set font sizes responsively based on its container's width. You can use this

Sieve is a jQuery plugin that allows you to quickly add an interactive search filter to any block of content.  

Responsive Nav is a tiny JavaScript plugin which helps you to create a toggled navigation for small screens. It uses touch events and CSS3 transitions

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with

Mosaic Flow is a Pinterest like responsive image or HTML grid plugin for jQuery.    Mosaic Flow - Features:

PowerTip features a very flexible design that is easy to customize, gives you a number of different ways to use the tooltips

OriDomi is a javascript library for folding up HTML DOM elements.   OriDomi - Features: zero dependencies fully

Taggd is a configurable jQuery plugin that help you create tags on images with, or without a popup.  

dropdown.dot.js is a jQuery plugin for super-flexible dropdowns based on dot.js templates.  

jDigiClock is a jQuery plugin inspired from HTC Hero Clock Widget.   This plugin accepts