What are some alternatives?
Typora - A minimal Markdown reading & writing app.
Sublime Text - Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features. Fully customizable with macros, and syntax highlighting for most major languages.
Visual Studio Code - Build and debug modern web and cloud applications, by Microsoft
Atom - At GitHub, we’re building the text editor we’ve always wanted: hackable to the core, but approachable on the first day without ever touching a config file. We can’t wait to see what you build with it.
Haroopad - Haroopad is a markdown enabled document processor for creating web-friendly documents.
iA Writer - Minimal Design, Maximum Focus