Simple Markdown is an open source markdown editor that (surprise) allows you to quickly and easily edit markdown files and then share them as you please.

If you find any bugs you can submit them here:
https://github.com/wbrawner/SimpleMarkdown/issues

If you'd like to contribute to the code you can find it here:
https://github.com/wbrawner/SimpleMarkdown

Also feel free to contact me directly if you have any questions or concerns :)