SudoKlue

What's the method to your sudoku madness? Strategies for solving these number-placing brain-teasers can be complex, so why not do the puzzles in SudoKlue? This clever freebie analyses puzzles and provides cell-by-cell solutions, setting you on the path to sudoku mastery.

SudoKlue generates random puzzles or lets you input your own. Use the pencil tool to mark the possibilities, then the pen tool when you're sure you know the solution. SudoKlue can give hints, find errors, and solve individual cells for you. Links to the SudoKlue Web site explain the different puzzle-solving techniques.

The free SudoKlue is a demo of the $US20 SudoKlue Pro. You can play only the easiest of the six difficulty levels; clicking higher-challenge selections pops up a nag screen. This keeps you from practising or receiving hints about most of the techniques, since only beginner hints appear at the Beginner level. However, even the basic SudoKlue sharpens your wits without making you sharpen a pencil.