Draft is a collaborative writing tool that makes you focus on writing and revising by giving users a simple interface. In Draft you won't find options for inserting images or messing around with font types. In Draft you just write. When you're ready to get feedback about your writing, you can invite someone to read your document by entering that person's email address. The person that reads your document can suggest edits. When the person reading your document is done you can accept or reject the suggested edits.
Applications for Education
For students who don't have Google Documents, Draft could be a nice tool for peer editing online.