Writedown‪!‬ 4+

No pdf export, no way (that I could find) to export the generated Markdown to another file, could only save the md).
Good otherwise, would like to see improvement.

A bit unstable, so save your work often. It also constantly nags me that the file on disk has changed and asks me if I want to reload it, even though the only thing that changed the file was me hitting save (it's like it just keeps checking if it changed since the file was opened, not if it changed since last save).

I was excited to find this app, since it seems to be one of the few markdown editors with live preview for 10.6. However, I cannot seem to get the app to function properly - I opened it immediately after downloading and nothing happened. No windows appeared, no instructions, no welcome screen, nothing. I tried to create a new document from the File menu, but again, nothing happened. I tried to open a new document with the same result. As a last resort, I uninstalled and reinstalled the program, and still nothing. I eventually gave up because I found an editor that worked on the first try, and other people may not have the same experience I had with this, but please beware that Writedown! may not work for you. EDIT: I also wanted to mention that their support page is a github page, which isn't particularly helpful for people (like me) who aren't familiar with navigating that site.