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.
GitHub users will appreciate Marked's built in GitHub Flavored Markdown processor, capable of handling fenced code blocks, line break preservation and automatic hyperlinking.
Marked is powerful enough to allow custom processors (shell scripts) before and after rendering. You can even take over the rendering tasks to incorporate non-Markdown languages.
Marked works with Scrivener, VoodooPad, MarsEdit, and other third-party apps, allowing you to use Markdown and see beautiful previews just about anywhere.
You can checkout some video tutorials here: http://bit.ly/1riW0IK or purchase Marked 2 at the link below for a limited time introductory price of $9.99.