Yajisan-Sokoban is a logic puzzle invented by Jamie Hargrove. A rectangular or square grid contains gray squares. The task is to move the gray squares vertically or horizontally (some squares may stay unshifted). Gray squares cannot cross the tracks of other gray squares and cannot move over other squares (gray squares can pass through numbered cells). A cell containing a number and an arrow represents how many gray squares are in the row or column pointed at by the arrow. If there is a gray square on top of a numbered cell, it plays no further role in the puzzle, and may be true or false. If a gray square passes through a cell with a number and an arrow, this numbered cell provides true information.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.