Jason Snell and Dan Moren have published an interesting article about markdown text editing using different editor apps on Six Colors.
The authors also provided a handy table summarizing the pros and cons of the different apps at a glance. From my own perspective, one aspect was missing from the table and the entire article: the ability to correctly handle markdown meta-data during preview.
|Feature||Taio||1Writer||Drafts||iA Writer||Textastic||DEVONthink To Go||Keep It|
Of all the apps in the table, iA Writer provides by far the best support for markdown meta-data. While other apps mentioned in the table restrict themselves to more or less tolerate meta-data, iA Writer goes one step further and supports the usage of meta-data to parameterize the markdown text.