Writing Kit is one of the many apps that supports markdown. That's in fact one of the reasons I picked it. Once you start to sync things you write on you quickly learn all your neat formatting may get lost. Markdown helps plain text files have formatting.
I love writing on my iPad, because it doesn't seem serious; I'm more creative because it's not "real" writing.
If you write for the Web, as I do, you'll enjoy Writing Kit. It offers Markdown -- no more complicated HTML code. Try it yourself, you'll like it.