Deddoanguru ("Dead Angle") is a logic puzzle invented by Naoki Inaba (Japan). A rectangular or square grid contains black circles with numbers. The aim is to divide the grid into regions. Each region contains one black circle. A black circle is an eye that looks in all four directions until a region border. The number in the cell represents how many cells of the region the eye does not see.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.