This is a freeware application by Hisashi Hoda, I don’t have any more information except for this very ancient site. None of the variations on the site work so don’t bother downloading them.
I’ve tested it out and an works really well although it opens in classic mode.
To unzip the file you will need to change the extension from .zip to .sitx then unzip.
The commands are
Cmd B toggles two differenct modes
Cmd F toggles full circle or full screen
Cmd P pauses
Cmd Q quits
