FoldingText is a still in development but quite usable new, um, well, it’s complicated:
FoldingText is a plain text outliner. As you type, FoldingText auto-formats your document into headings, lists, and paragraphs. Fold your headings to see the big picture. Focus on a heading to view the details. FoldingText is simple, yet surprisingly adept.
Yes, but that is only part of the story because, well, it has to do lists and timers built in as well. Oh, it is also built with Markdown in mind (with auto-formating and syntax hiding).
Like I said, it seems kind of crazy until you start to use it for a bit. Then, it seems like magic.