Concentrate...
This program based on a technique of training and testing of concentration of attention of pilots. The game has two modes - training and test. The test is available if you complete workout in less than 50 seconds. Training reports are stored in the database and, based on chart your progress is built. Also you can save your best achievements on the server and compare them with other players. Catching only 20 minutes a day you will improve your memory, attention and concentration.
How to play. It's simple to find all the numbers, alternating black and red (in training mode from 10 to 25, in test mode from 10 to 39)
Good luck.