TAG: Marked 2
Marked 2 is a previewer (not an editor) for Markdown, MultiMarkdown and other text markup languages. It updates live every time you save your document in your favorite text editor, comes with writing analysis tools, and is powerfully flexible.
Marked provides document navigation and statistics, proofreading tools, multiple export formats, and much more. Marked comes with 9 preview styles built in (including GitHub), and you can add unlimited custom styles of your own.