Folding Text (US$14.99) is a handy Markdown-based editing app for the Mac. Brought to you by the developers of WriteRoom and TaskPaper, it displays Hog Bay Software's commitment to clean interface design supporting strong text features.
To say Folding Text is a to-do list editor that allows you to show and hide sections is to miss a great deal of the application's nuance. Its enormous feature set makes me think that the people who develop this tool also use this tool, and are growing it to accommodate real-world practical needs.
For example, the app offers a checkbox-based "todo" mode and a time-annotated "timer" mode. These help you keep track of tasks to complete as well as when they should occur. By renaming your file with the appropriate extension (myfile.todo or myfile.timer), you unlock feature sets that add further structure to your lists. The video below demonstrates these.
Keeping the isolated WriteRoom philosophy in mind, Folding Text can also "focus" on a portion of a list. This allows you to concentrate on just one part of your organization work at a time. For example, if you're working on a complicated schedule, Folding Text can hide away extraneous bits until you're ready to deal with them.
What Folding Text delivers is a clean Markdown-based editor with a lot of end-user control over what you see and what you hide. For anyone who works with lists and wants a simple and uncluttered way to edit them, Folding Text provides a worthy entrant into a field dominated by the Omni Group and Cultured Code.