Penflip - Typewrite is a real-time collaborative writing environment with Markdown support, versioning and Dropbox syncing. Alternatives to Penflip for Web, Windows, Mac, Linux, iPhone and more.
Calmly Writer - Distraction-free text editor for Mac, Windows, Linux and ChromeOS.
Typewrite - The California Typewriter Company provides service and sales for all makes and models of typewriters, fax machines, printers, calculators, and even word processors.
Writebox - Writebox is a simple and distraction-free text editor for Chrome and iPhone/iPad.
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
Stashany - Online notepad for developers