It does not do much. You can
- Add a leaf next to the current selection
- Add a child of the selected leaf
- Duplicate the selected leaf (and its children)
- Delete the selected leaf (and its children)
- Underline, bold, and italicize text
You can print or export an item (with or without children) or everything to rtf and odt. You can also import txt or odf files. You can save and open files as templates (which are just ordinary files that can be re-used). The files themselves are saved in human-readable XML format with the extension of "lfn".
That's it. You can call it an editor. You can also call it an outliner. There is no reason why you could not use Markdown or any other markup in the leaves.
It's not fancy, but it does what it does elegantly. I just had to buy it, though $9.99 is perhaps a bit steep.