Do you want to have more fun with Sudoku?

SudoKoach™ is a Windows program that makes solving Sudoku puzzles more fun by doing the tedious work for you. It also gives you hints and tips on advanced solving strategies that will make you a better Sudoku player. (What is Sudoku, anyway?)

When solving all but the simplest Sudoku puzzles by hand, you eventually reach a point where you have to figure out what numbers are possible in each unsolved cell. While this task isn't hard, it's timeconsuming and errorprone, so it isn't much fun.
SudoKoach does this work for you, so you can get right to the more interesting and challenging aspects of solving the puzzle. SudoKoach doesn't solve the puzzle for you. In fact, the only work that it does is work that you can do yourself (but isn't much fun to do).
In addition, SudoKoach has 36 different solving strategies built into it. These strategies can conquer 99.5% of all Sudoku puzzles!
Solving Sudoku puzzles with SudoKoach is more fun because:
Plus, you can:
Click the button below to download the 30day free trial of SudoKoach to see how much more fun Sudoku puzzles can be!
"I have the program installed and it is AWESOME! I like it as a teaching tool and also for problemsolving. I'll be honest with youI have quite a few sudoku programs on my computer and also handheld games, and your SudoKoach is THE BEST! Thanks!" David R. 
Windows 95/98/NT4/2000/me/XP, and all versions of Vista.
US$12.95 for one computer; $2.50 for each additional computer. You will be able to download SudoKoach immediately after placing your order.
For an additional US$5.00 we will mail you a CDROM (there is a $3 shipping charge for this if you are not in North America). The CD has simple pointandclick installation and includes additional shareware and other software that is too big to send via download. The CD also serves as a backup in case you ever need to reinstall SudoKoach.
The current version is 2.3. Read a list of the new features in this version. Registered users of 2.0 and later can download a free update to 2.3.
Registered users of version 1.0 or later can also download a free update to 2.3.
When SudoKoach displays a Sudoku puzzle, it shows you which numbers are possible in each unsolved cell, like this:
The big numbers indicate cells that have already been solved; the other cells contain smaller numbers that indicate which values are possible. With this information, you can immediately start looking for the more interesting patterns. Here is an example:
Solving cells and eliminating possibilities are the two tasks you do most often in SudoKoach. Therefore, they are extremely easy to do.
If you find that a cell has no possibilities, you must have made a mistake somewhere along the way. To fix this, simply undo as many of your moves as needed to remove the problem. You can check as often as you like to see whether your moves so far have been correct.
Many cells are solved by observing that they contain a possibility that cannot appear in any other cell in the row, column, or 3x3 box. SudoKoach simplifies this search with a feature called Highlighting. When you highlight a value, all unsolved cells that contain the value as a possibility are shaded so that they are easily visible.
In the puzzle below, the value 5 has been highlighted. Just look across each row, down each column, and in each 3x3 boxif you find exactly one highlighted cell, then that cell must be a 5:
Highlighting makes it easy to spot these solutions:
If you get stuck solving a puzzle, you can ask for a hint. A big hint either solves a cell or removes possibilities from one or more cells. In either case, the hint will explain the logic behind the suggested move. The hint below describes a strategy called XYwing:
If you need a hint but don't want to be given an answer, ask for a "little hint"this will tell you what to look for next. In the puzzle above, a little hint would have told you: "Look for an XYwing."
A "medium hint" is like a little hint but also tells you the number to look for. In the puzzle above, a medium hint would have told you: "Look for an XYwing with the value 1."
SudoKoach provides coloring, a powerful tool to help you find moves. Here is an example:
We are trying to decide whether cell 2,2 should be 3, so we color it green (to indicate "3"). We then color the cells that can no longer be 3 red (to indicate "not 3"). Row 3 and column 3 each have only one cell that can still be 3, so we color them green. This prevents a few more cells from being 3, so we color them red.
Look in box 8 (the center box in the bottom row of boxes). It has no cells that can be 3they are all blocked by one of the green cells. This is impossible, so setting cell 2,2 to 3 must be a mistake, and we can eliminate 3 as a possibility from that cell.
This sure beats making the move, eventually getting stuck, and then having to erase all the incorrect moves you made (if you could remember them all, that is)!
Learning a new strategy is easier if you are able to practice it. For this reason, SudoKoach has a practice mode. You choose a strategy, and SudoKoach will generate a puzzle in which the chosen strategy is the next move. This makes learning the strategies a lot faster.
Also, the help file tells you the frequency with which each of the strategies appears in puzzles. This is particularly useful when choosing which strategy to learn next: start with the more common strategies, and work on the less common strategies later.
To change the size of the puzzle, just resize the window. The numbers automatically shrink or grow to fit the size of the puzzle.
You can also solve puzzles from books or newspapers with SudoKoach. After you've entered the puzzle, SudoKoach checks it to verify that the puzzle has exactly one solution. Then you can solve the puzzle just as if SudoKoach had created it for you.
You can print puzzles to solve when you're away from your computer, or print puzzles you've created for your friends to solve!
"I just recently purchased your program and love it! Many thanks for an excellent program." Dr. Allan P. 
It's a lot more fun to play SudoKoach than it is to read about it! Why not download the 30day free trial and try it out?