Everyone knows what it's like to go back and forth with someone putting the finishing touches on an essay. It's hard to find time for both parties to sit down and link up over multiple platforms, so what ends up happening is you just throw the essay, resume, whatever it is, back and forth via email. This sucks. There's no continuity to the conversation.
Last week I was working on a final paper for my negotiations class with my group, and we ended up just having one person outline the essay, another write it, and another person edit it. There was no continuity to the process, and half our group wasn't even involved! That's why we built PeerReview. It's a video chat tool that integrates with Google Docs to allow users to have a face-to-face conversation while they work out the kinks in a document.
The cool thing is that this doesn't just work with written documents. You could use it with excel sheets or a set of slides too.