Topcoat is a very neat and clean library of CSS classes specialized in form elements: buttons, checkboxes, sliders, etc. A super easy way to make your website or app look good in minutes.
Want super-looking checkboxes and radio buttons for your new web app? Then try iCheck, a jQuery plugin which allow you to easily customize radio buttons and checkboxes. iCheck is easy to use and comes with various skins and color schemes.
CSS only responsive navigation
Responsive layouts are very popular on the web right now, and this is definitely a good thing in my opinion. Here is a downloadable and reusable responsive navigation menu, made in CSS only.
Almost Flat UI
Based on Foundation Framework, Almost Flat UI is a complete HTML/CSS/JS framework to build your site on. It looks really clean and professional. Definitely worth a try!
Chart.js is a dependency free, lightweight and object-oriented tool to create client side graphs. It features 6 different chart types and is very easy to use.
When building websites or apps, you often need placeholder images. This very handy service generates random images at the requested size. Super useful!
jQuery Panzoom is a progressive plugin to create panning and zooming functionality for an element. Panzoom supports the same browsers as jQuery 2.0 and can be used with jQuery 1.9.0+ or jQuery 2.0+.
If you want to be able to create perfect looking scrollbars, then you should definitely have a look to this tiny jQuery plugin. It helps you to create customized scrollbars with no css change on any original element.
A lightweight, easy-to-use jQuery plugin for fluid width video embeds. It was built by was built by Chris Coyier and Paravel.