Tune your brain? Reaaaallly?

Last night I downloaded the Iphone app called Tune your Brain. It is said to tune your brain activity. It says the software works by sending a base tone to one ear, and then a slightly different tone to you other ear, which causes your brain to resonate as the tones go in and out of phase. The program allows you to set the tone anywhere from 4.0 Hz-40.0 Hz. 40 is for activating your brain, say before an exam and 4 is used to put your brain in relaxation for deep sleep. This process is called binaural beats and here is an informative Wikipedia page explaining the phenomenon.