CONV. - Convert YouTube video to MP3, GIF or MP4
riv.yt - A minimalist way to view and share YouTube videos
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
Cevoid - Shoppable visaul user-generated content for e-commerce
Yout - YouTube to Mp3 Converter
Envite - An integrated social chat for your e-commerce site