tramSwipe (or Smart Swipe if you can read in both directions) is simple and useful timekiller for iPhone 4s/5/5s/6/6 Plus/6s/6s Plus. It will teach you to add up numbers in mind much better.
Why tramSwipe? Because both left and right swipes during game have to be Smart = tramS. :)
The goal is do not let numbers to fall down. At start you have perfect balance, two zeros.
When the game begin, random numbers will fall down. Swipe these falling numbers left or right. Left or right number will increase. Greater number will go down. Try to keep the balance. If any number fall down, the game will stop.
When you reach the top score 2147483647, you will get gold game title. If you play again, highscore will reset.
Thats all. Good luck!