Iconvault allows adding any number of images by simply drag ‘n’ dropping them to the uploader and creates the necessary files (font and CSS rules) automatically in seconds.
Skel.js is a tiny JavaScript framework what have a 12-column grid system (~6kb gzipped and minified) that simplifies building responsive layouts very much.
noUiSlider is a Fantastic Range Slider For jQuery with support for single or double handles, custom starting values, vertical/horizontal orientation and the ability to get /set values.