Sashigane (from Japanese, literally "carpenter's square") is a type of logic puzzle published by Nikoli. The goal is to divide the grid into L-shaped regions. The two "legs" of a region must be exactly one cell wide. A circle represents a cell in which an "L" must bend (the grid contains circles not for all regions). A region must have the same number of cells as a number in a circle. An arrow marks the end of the region's "leg"; the arrow points to the cell in which the "L" bends.
Cross+A can solve puzzles from 4 x 4 to 30 x 30.