algebra.js

Build, display, and solve algebraic equations in JavaScript.
http://algebra.js.org
solve and display equations like Mathematica

howler.js

howler.js makes working with audio in JavaScript easy and reliable across all platforms.
https://howlerjs.com/
rate up or splite multi audio tracks like a DJ

Lorem Ipsum

Lorem Ipsum is simply dummy text of the printing and typesetting industry.
http://www.lipsum.com/
generate random Latin articles without repeating or embarrassment
for node.js: https://github.com/traviskaufman/node-lipsum

Freewall

Freewall is a cross-browser and responsive jQuery plugin to help you create many types of grid layouts
http://vnjs.net/www/project/freewall/
just like winPhone

ZooMove | jQuery Zoom Image

http://emersonthompson.com.br/zoomove/
https://github.com/thompsonemerson/zoomove
It's a plugin developed with jQuery, that allows to dynamically zoom images with mouse-over, and view details with mouse move.

jQuery Rippleria

https://github.com/nsept/rippleria
A lightweight yet customizable jQuery plugin for implementing Material Design inspired ripple click / tap effects.
clicking in a material design way

Turntable.js 2.0

Responsive JQuery Slider
"a flipbook made with Javascript"
https://polarnotion.github.io/turntable/

Vide.js

Easy as hell jQuery plugin for video backgrounds.
http://vodkabears.github.io/vide/
cool video background

Trianglify

Algorithmically generated triangle art
http://qrohlf.com/trianglify/
gorgeous low poly background

Tooltipster

https://iamceege.github.io/tooltipster/
A flexible and extensible jQuery plugin for modern tool tips.

Timedropper

http://felicegattuso.com/projects/timedropper/
a jQuery time plugin
such an eye candy

Reference List

http://designmodo.com/free-jquery-plugins-2016/