PreFlight - Preflight is an Automated Web Testing tool. Allows everyone to automate Web UI tests.
FileInfo.com - FileInfo is the central file extensions registry and contains a database of over 10,000 file types.
The YouTube Thumbnail Game - Guess which YouTube video thumbnail has more views
Convertio - File Conversion in the Cloud
Videogram - Auto create interactive thumbnails (GIF card) of video
FILExt - Open, view and convert files online