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.
See whats new: http://marked2app.com/help/Whats_New.html
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.
MultiMarkdown processing is provided for writers, complete with tables, footnotes, file transcludes, and other MultiMarkdown-specific features.
GitHub users will appreciate Markeds 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/or instead of the built in processors, allowing custom Markdown processing and use of non-Markdown text processors.
Marked works with Scrivener, Ulysses, MarsEdit, Highland 2, iThoughtsX, MindNode, and other third-party apps, allowing you to use Markdown and see beautiful previews just about anywhere.
See the video tutorials! http://bit.ly/1riW0IK