Puzzle games
Quiet games for a sharp mind. Every board can be worked out by thinking it through, and there is a new one waiting as soon as you finish.
Tenwise
Slide numbers together to make 10, then 100, then 1000. Add up, but never go past a round number.
Pencil Mines
A mine-clearing logic puzzle on paper. Read the numbers, flag the mines, and never step on one.
Nonogram
Read the numbers, fill the squares, and a hidden picture appears. New puzzle every day.
Sudoku
Nine rows, nine columns, nine boxes, and a fresh puzzle every time you sit down.