ProgressJs is a JavaScript and CSS3 library which help developers to create and manage progress bar for every objects on the page. You can design your own template for progress bar or customize it simply.
You can use ProgressJs for show the progress of loading contents (Images, videos etc.) on the page to the users. It could be used on all elements including textbox, textarea or even whole body.
It is light-weight, easy to use, easy to customize, totally free and open-source.
Examples can be found here: http://usablica.github.io/progress.js/
Download the script here: https://github.com/usablica/progress.js/releases