From the screen shot on that page, it's nice free program which lets you do a few different things.
*edit: yea, just looked - the company no longer support freeware, but now supports a paid version called PrintKey-Pro. But you can still get the old freeware version from the link above.
(hide) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (show all tips)