It's a terrific project, well executed.
To all the naysayers: You're right that you have no reason to trust ANY online tool or channel with your secret documents. Open source is best, etc. But, this crypto tool is more about hiding data than securing it. So, for instance, maybe you don't care if this site "steals" your resume as long as your boss doesn't see it. So, relying on their encryption works for that. Still, if you want to keep secrets from everybody, just encrypt your files before hiding them with this. Either way, pixelator is still a viable (and kind of fun) tool to use.