Raise a tower on every square. Each row and each column holds every height once.
A number at the edge counts the towers seen from there. A taller tower hides the shorter ones behind it.
Tap — raises a tower by one. After the tallest, the square is empty again.
Hint — shows the next step and why. Press it again to fill it.
Black-topped towers are fixed. A dashed mark means a repeat or a miscount.
More controls
Arrows move. Enter or Space raises a tower. A digit sets a height; 0 or Delete clears. Z or Backspace undoes. H hints.
Restart clears this puzzle; Undo restores it.
Settings has a flat view: the same board as a plain grid of numbers.