Haroopad is an extensively built, cross-platform Markdown document processor for Linux, Windows and Mac OS X. It enables users to write expert-level documents of numerous formats including email, reports, blogs, presentations, blog posts and many more.

It is fully featured with the following notable features:
Easily imports content
Also exports to numerous formats
Broadly supports blogging and mailing
Supports several mathematical expressions
Supports Github flavored Markdown and extensions
Offers users some exciting themes, skins and UI components plus so much more

Github : https://github.com/rhiokim/haroopad