Typora

Typora gives you a seamless experience as both a reader and a writer.
It removes the preview window, mode switcher, syntax symbols of markdown source code, and all other unnecessary distractions, replacing them with a real-time preview to help you concentrate on the content itself.

Features:
Markdown support including tables, code fences with syntax highlight, LaTeX, table of contents
Cross-platform
The real-time preview and WYSIWYG features
Beautiful interface and custom CSS theme support
Easy export