Enhance your calculation ability, instantaneous memory, and peripheral vision with “Double”!
This application will sharpen your concentration just by playing for a short moment.
It’s very simple to play.
Keep doubling the numbers showing on the screen and type the answer as fast as you can. Watch out, the keyboard layout is randomly shuffled.
Challenge your best calculation score within the time limit.
– 3 difficulties; Easy/Medium/Hard
The harder you set the difficulty, the bigger the given number is.
Calculation will be more difficult depending on the difficulty, but makes it easier to gain high score.
– Register high score
The app can save your high score every time after the time limit.
Use the app for everyday brain training.
– Win the first place in world ranking
Register your best score on the world leaderboard and compete against players from all over the world.