Goal: Fill the grid so every row, column and box contains each digit exactly once.
Thermometer rule Along each thermometer, digits must strictly increase from the bulb (the round end) to the tip. The bulb holds the smallest digit on its thermometer.
Tap a cell then tap a digit to place it. Use Notes ✎ to pencil candidates, 💡 Hint to reveal a digit (costs stars), ⌫ Erase to clear.
Every puzzle has exactly one solution, verified by a solver.