As I recently wrote, I’m now using Ulysses for my writing needs. Before that I was using WordPress.app. For To-do, I’m using Things on the Mac and on iOS. I recently read an article from The Sweet Setup on how you can combine Ulysses with Things in order to help you manage your writing tasks.
The idea is to create a task in Things for each sheet in Ulysses as those are in fact a task you are accomplishing. In order to reach your sheet from Things, you will paste a URL in the note field that is a call-back call to Ulysses. That is very nice and very easy to create. Head on to the article to learn how to do it.