MarkdownMail is a very cool little app that lets you compose emails in Markdown and convert to HTML right on your iOS device. It works exactly as advertised. You can write or paste a chunk of Markdown text, preview it in HTML, then send. Bonus: It even supports TextExpander touch.

While I often write in Markdown and MultiMarkdown in Simplenote, I never thought about doing the file conversion on an iOS device (until now). MarkdownMail provides a whole new world of possibilities by giving you a Markdown converter that goes everywhere you go.

Beyond its obvious use (sending HTML-based emails to people), MarkdownMail provides a nifty way to make HTML-formatted blog posts from your iOS device.

While some blog platforms like Tumblr will convert Markdown to HTML for you, most don’t. But many blog platforms will accept HTML and post it as-is.

I can envision a mobile workflow where you write in Simplenote and use MarkdownMail to do the file conversion.

At only $1.99, MarkdownMail is probably a must-have productivity app for the mobile web writer. If you come up with a creative use for MarkdownMail, share it in the comments.

Thanks to John Gruber for sharing the link to MarkdownMail.