Dev7studios

Typewriter completely removes the “Visual Editor” feature in WordPress and replaces it 
with a simple Markdown editor so that you can join sites like StackOverflow and Github in writing in the 
simple and growingly popular <a href="http://daringfireball.net/projects/markdown" rel="nofollow ugc">Markdown format</a>.
For the more technical among you, Typewriter removes the TinyMCE editor and defaults to a Markdown specific “Text” editor 
and parses the output using MarkdownExtra.

Typewriter

Typewriter replaces the Visual Editor with a simple Markdown editor for your posts and pages.

MaldersIO

This plugin supplies a simple, light-weight, inline typewriter function utilizing a span tag with the class of txt-type on any page, or post.

TypeWriter Anywhere

This plugin supplies a simple, light-weight, inline typewriter function utilizing a span tag with the class of txt-type on any page, or post.

Typewriter vs TypeWriter Anywhere