The goal is to fill the 9x9 grid with numbers from 1 to 9.
- Each row must contain the numbers 1-9 without repeating.
- Each column must contain the numbers 1-9 without repeating.
- Each of the nine 3x3 subgrids must contain the numbers 1-9 without repeating.
Tap an empty cell to select it, then tap a number below to fill it in.