at $10 you get this which is very much like the game collection management in SigmaChess with marginal piece graphics... whereas for $15 you can get SigmaChess with its engine and all its features including excellent game library management and annotation, etc., (and more coming in Sigma 7).

That having been said, this is a fine program with a simple enough interface, but I think as far as competition goes it is priced too high. The most encouraging thing, though, is to see another piece of chess software released on osx!