Brett Terpstra just released a nifty utility called URL Preview, which works in conjunction with his other Markdown services.
Since moving to Camel, I have been using Byword for all my writing on both OS X and iOS. I was previously using MultiMarkdown Composer by Fletcher Penney (the creator of MultiMarkdown) on OS X due to all the features included with MultiMarkdown spec. However, since the npm plugin Camel uses to parse Markdown markdown-it does everything that MultiMarkdown Composer did, and since I greatly prefer Byword’s interface, I’m using it full-time (again).
I recently started using another utility from Brett called SearchLink. Using that in conjunction with URL Preview makes writing significantly easier and less stressful, because it allows me to just write in Markdown, and worry about all the hyperlinks once I’m finished writing.
While both are free utilities, I’m sure Brett wouldn’t mind a few bucks tossed his way for the trouble. Head over to his site for lengthy how-to’s for both SearchLink and URL Preview.