Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.
CONV. - Convert YouTube video to MP3, GIF or MP4
Upcoming.org - A simple way to share and discover interesting events
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
Colloq.io - Discover a new way to the conferences you like.
Yout - YouTube to Mp3 Converter