The program file name
"Sudoku" game. KolibriOS 0.7.7.0 distribution contains it.
Aim and rules of the game
About the rules of this game read here: 
Press "N" key to start a new game.
Press "+" or "-" keys to change puzzle difficulty (minimal difficulty is 0, maximal is 9)
To input a number into the selected cell just type it with the keyboard
Use arrow keys to select cells.
Press "C" to test solution.
Press "Space" key to see the solution of the puzzle.