With Notes on, a tap adds a pencil mark and a hold of about half a second places the answer. On a phone, the board sits low, near your thumb.
Calm Sudoku on warm sand, with short lessons and hints that stay quiet until you ask. After it has loaded once, it keeps playing offline, and you can install it from your browser.
Switching pen and notes, over and over, is a lot of extra taps.
Here, you leave Notes on. Pick a number, then tap an empty square to add a pencil mark. Hold the square for about half a second and that number is placed as the answer. You don't switch modes back and forth.
A board at the top of the phone is a stretch for your thumb.
Here, the number pad sits above the board, and the board rests low on the screen.
