Cloud: Dropbox, Evernote, Box, Google Drive
Draft functions as a simple space in your browser's window where you can write, and work with others on any document. The app lets you leave comments on the documents you've been invited to edit, and view edits from previous versions of the document, which makes it a fantastic collaborating tool. Draft also features a Hemingway mode, that prohibits you from going back to edit your text, allowing you to write drunk, edit sober.
Draft's Chrome extension allows you to click on any text field on the web, and open a new Draft in the app. Click again, and you'll bring your text to that field.
One downside of the editor is that Markdown doesn't work on the fly. To see how your text looks all formatted, you'll need to click in the menu or use a hotkey, and then do it all again to go back to editing mode. Overall, the interface is not exactly what one would call smooth, but that's the downside of being a web application.
Draft is unique in that, other than being a text editor, it also offers users professional copy editing services. They guarantee a full refund if you don't like the results, and promise that the editing staff is college educated and working under a strict NDA. Results should be received in under 24 hours.
Doesn't work smoothly
No desktop application