Best Kakuro Software today announced the initial release of Best Kakuro for Mac. Best Kakuro has been available for Windows systems since last March, and due to popular demand has now been released for Mac OS X. Kakuro, also known as Cross Sums, is a challenging number puzzle, solved in a crossword style grid, where the black squares contain the sum of the adjacent white squares. The puzzles are created in five difficulty levels — Easy to Killer — with grid sizes ranging from 8×8 to 14×22. Best Kakuro sells for US$15, and a free demo version is available.