I recently bought a little chess program for my Ipod, which doesn't even play extremely badly, since on the hardest level (while playing in the train f.i.) I've only won one so far (out of, say, 4), but that was one I quite liked, since it involved a classic bishop sacrifice that could have been copied directly from Vukovic's "The Art of Attack in Chess". The chess program didn't spot it, and when I checked it with Fritz, it took relatively long and Fritzy goes wild on the variations. The Bxh7+ was an instant move, and an instant winner, thanks to Mr. Vukovic.