Writerrific is an awesome writing app for your favorite web browser It works teriffic on almost any web browser, except for IE8 or lower. It's awesome to use on mobile devices too!*
Writerrific uses the awesome Markdown syntax. It basically processes plain text with a special syntax to rich text with a beautiful look.
Writerrific uses Markdown.Converter.js to convert the plain text you enter into rich text. It is one of the best client side markdown converters currently in existence.
We also use Bootswatch to make our app look awesome.
And for our awesome "Distraction Free"-mode we use Screenfull.js, because it was the easiest Fullscreen API library for jQuery.
Thanks for checking out Writerrific!*And probably the best thing, it's open source.