#1 jQuery File Upload
As the name suggest, jQuery File Upload is a jQuery plugin used as a widget in web pages for uploading files. Some of the best features of this plugin are simultaneous uploading of multiple files, progress bar display, drag and drop from the desktop, cancel and resume of uploads, image previews while uploading, etc. This plugin also supports chunked upload, which means larger files can be uploaded in smaller parts. It is compatible with any server side platform like PHP, Ruby, Python, Node.js, etc.
#2 Ideal Forms
Ideal Forms is a jQuery plugin for building HTML5 compatible forms. It supports form validation, customizable input types (select, file, radio, and checkbox), keyboard support, localization, custom datepicker using jQuery UI (fallback). This plugin works on Google Chrome, Opera, Firefox, IE8+, iOS5+, and Android 4.0+ browsers.
#3 Form Accordion
Form Accordion is a jQuery plugin used for hiding and displaying related fields conditionally. This plugin can save you lots of time when building a form for a wide range of audiences. You can add conditions to specify which field to appear next if a particular value is selected in the current field.
#4 TextExt Plugin
TextExt Plugin is also a jQuery plugin that allows you to easily fill HTML text fields with suggestions. As you start typing in the text input field this plugin will show you a predefined set of suggestions matching what you have typed. TextExt is a great tool for making searches faster in web pages.
Sisyphus.js is a script which helps visitors store form data locally in the browser. This script comes to the rescue when you are filling out a large form and all of a sudden you hit the close button of the browser accidentally. This script will fill the forms out for you automatically the next time you reload the page. This script is supported in Google Chrome 4+, Firefox 3.5+, Opera 10.5+, Safari 4+, and IE8+. For older version of IE (6 and 7) you have to load jStorage before loading Sisyphus.js.
#6 jQuery Credit Card Validator
jQuery Credit Card Validator validates an input field every time the user inserts a value. It recognizes the card and highlights the card type when a correct number is provided. Some of the supported card types are American Express, Laser, Diners Club, JCB, Discover Card, Maestro, MasterCard, Visa, and Visa Electron.
FitText is a jQuery plugin to achieve responsive font types in your website. It resizes the headings in your website as per the ratio. It ignores the font size and uses minFontSize and maxFontSize to make the font flexible. If you are building a responsive or fluid design then you can use this plugin to resize the headings.