Chart.js - Easy, object oriented client side graphs for designers and developers.
CONV. - Convert YouTube video to MP3, GIF or MP4
D3.js - D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS.
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
Google Charts - Interactive charts for browsers and mobile devices.
Yout - YouTube to Mp3 Converter