The program is no longer updated. Last version, 2.4.4, released in October 2012, can be still downloaded from the official website.
I use it all the time for quick breaking-down of tasks and problems. It's fast, customizable, and, most of the time, easy to use from the keyboard without even touching the mouse. Too bad the author seems to have forgotten about his app as there are yet some bugs that might be worthwhile to fix...
UV Outliner has a nice interface but it lacks import of any sort. Requests for import from opml or text have gone unanswered on website.
It exports nicely to text and html format.
Our users have written 2 comments and reviews about UV Outliner, and it has gotten 34 likes