A quick 3 minutes introduction to Bower( Javascript Package Manager)

Link here.

A nice and minimalistic progress bar

Link here.

Coolest ever page transitions !

Link here.

Preload assets(eg. images) on your page

Link here.

Know which css is going unused

Link here.

Tired of figuring out how to vertically(or horizontally) center your elements? Here's a javascript plugin!

Link here.

Get placeholder images according to your need when designing a new web app

I could find not one but three of them. Besides choosing sizes, we can also choose type of images we want from categories provided, all for free.

Lorem Pixel
Fakeimg
Placeimg

Easy library to make charts and graphs

Link here.

Want to minimize your minimized files more through structural optimization?

Link here.

A command line tool to generate css sprites.

Link here.

Sencha gives you a free way to resize your big images on smaller screens.

Link here.

Count character, words and paragraphs entered by a user live

A very small plugin that has no dependencies.
Link here.

A plugin if you want to use excel/spreadsheet formulas.

Link here.

Ready css3 animations

Link here.

Know the resolution and ppi of any screen

Link here.

Write better html using HTML inspector plugin

Link here.

Beautiful analysis and visualization tool

Link here.

A javascript library, Cytoscape.js for analysis and visualization

Link here.

Simple triangular list bullets using css

Link here.

Check user's input without js using regular expressions and HTML5 !

HTML5 now allows you to check input attributes of the user using regular expressions without the use of any javascript using "pattern" attribute -

A simple example for email check -

<input type="email" pattern="[^ @]*@[^ @]*" value="">