Place stars so that every row, every column and every outlined region holds exactly two of them.

No two stars may touch, not even at a corner.

Crosses are your own notes of where a star cannot go; only the stars are the answer.

Tap a cell to cross it out, tap again for a star, once more to clear it. Drag across cells to cross out several at once.

A star turns red when it touches another, or when its row, column or region holds too many.

Learn the solving techniques