There's also full version of this app (Simple Number Game!) which includes slightly bigger grids and no advertising!
Full version: https://itunes.apple.com/app/id1069629092
Simple Number Game starts with empty grid and the goal is to fill the grid with ascending numbers starting from 1.
The rules are very simple:
To place a number horizontally or vertically, you must leave two squares between the consecutive numbers. To place a number diagonally, you must leave one square between the consecutive numbers.
– The game shows possible locations for the next number. This feature can be turned off.
– Size of the grid is editable. Grid sizes for different devices are shown on the table below.
– The game keeps record of solved grids.
Now you can undo your previous moves by swiping left on the screen.
Minor bug fix with closing the settings menu by tapping outside the menu window.
With Family Sharing set up, up to six family members can use this app.