We actually made that product first! - http://www.notable.ac http://www.notable.ac is similar, but made specifically for students, documents are organized by c

We actually made that product first! - http://www.notable.ac http://www.notable.ac is similar, but made specifically for students, documents are organized by course and notes can be made public/private/shared with friends. It does take a bit more work to setup, because you have to upload the documents to the site first (we process them into images on the server, and support Word/Powerpoint as well as PDF). We had trouble getting traction in the education space - So we built the Chrome version, which works much better for single documents and for uses outside education. But we're still keeping notable.ac running so feel free to give it a try.