TaskPaper 2.2.3 from Hog Bay Software (http://www.hogbaysoftware.com/products/taskpaper) is now available in the Mac App Store, and for a limited time you can get it for US$4.99. It will switch back to $29.99 on Friday, April 8th.

TaskMaker is a list maker for Mac OS X 10.6 or higher. Its plain text file format let you integrate into your workflow in a variety of ways.