Daniel Jalkut over at Red Sweater has updated his crossword-solving application, Black Ink (formerly MacXword), to version 1.0.7. This definitely seems like a niche piece of software (not because only a few people do crosswords-- almost everyone does), but because I don't know anyone who wants a piece of software to help them get puzzles done.
Still, I'm betting that the people who enjoy Black Ink really, really enjoy it. Apparently the program even downloads puzzles "on the go," so if you're not already a crossword fan, maybe it'll turn you into one. The new version adds a menu item for zooming in or out of puzzles, a few interface tweaks, and "correctly-solved detection for puzzles with multi-character answers." I never knew those existed, but there you go.
Black Ink is available for $24.95 over on Red Sweater's site.