Principle of the game :
A. A table of 4 rows on 4 columns, 16 cells, numbers from 1 to 15, one cell empty or indicated by 0 for screen readers
B. The app is choosing randomly the numbers in the cells
C. You have to arrange the numbers from left to right as follows:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 empty