Mobiriti ("Mobility") is a logic puzzle created by Naoki Inaba (Japan). A rectangular or square grid contains circles with numbers in some cells. The aim is to blacken some cells of a grid. Cells with circles can not be blacken. A number in a circle indicates how many empty white cells can be reached from that cell by moving horizontally or vertically.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.