From Pocket Express:
Award-winning PocketChess Deluxe has everything to challenge and entertain new and returning players. Easily customize your difficulty-level, personalize your game play, create color schemes, and more.
PocketChess contains robust skill-building features including chess problems, a 3000+ game library of theGrand Masters, undo moves and hints. With full PGN support, you can add new games and problems to your chess library in just a few quick steps. Plus, the included Desktop Companion allows you to categorize and organize your growing game library. Learn to play, improve your skill, or challenge a friend with this popular chess program for the Palm OS.