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.
Typewrite - The California Typewriter Company provides service and sales for all makes and models of typewriters, fax machines, printers, calculators, and even word processors.
Pine - A lightweight, modern macOS markdown editor written in Swift
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
EME - Elegant Markdown editor
ByLine - The easiest way to follow your favorite writers on the web