Zoomed in: drag with two fingers (or scroll) to move around.
How to play
Tap a cell to cycle × → ★ → empty. Drag across cells to cross out several at once. Every puzzle has exactly one solution, reachable by direct deduction only: you never need to guess or try something out. Stuck? Hint makes the next deduction and says why. Keys: arrows move, space cycles, x/s set.