The brain has two hemispheres that operate somewhat independently from one another. The two hemispheric structures of the brain are connected by a large nerve, called the corpus callosum, which sends information back and forth between the two sides of the brain. In most people, the left hemisphere controls language, logical thinking, and analytic processes and the right side contains the centers for emotion, intuition, and non-linear creative thinking.
* Headphones/Earbuds are Required for Binaural Tones to be Effective as the Left Ear and Right Ear Audio must be isolated for the Brain to perceive the inaudible low-frequency difference between the two sides. ** Changes to Orientation Support: With the upcoming arrival of several new devices with new screen-sizes and aspect ratios, iOS 8 required a re-write of our iPhone and iPad UI to support these devices, and as part of that, we have returned the app to a Portrait-only view for now. Once we know what these future screen dimensions and Aspect Ratios are, and have time to work with the real devices, we can implement a new Landscape UI for the iPad.

Brainwave entrainment is clearly NOT an effective standalone treatment for mental illness, but it may be an effective adjunct treatment in certain individuals. It should also be mentioned that when using brainwave entrainment, you may want to have a specific purpose in mind. If your goal is to relax, yet you’re using a protocol that is stimulating, you may falsely conclude that it doesn’t work even though you’re using the wrong protocol.
Brain Sync audio programs deliver pure and precisely tuned sound frequencies to the brain to drive brain activity into high level states of mind. These are brain states known as Alpha for heightened creativity and deep relaxation; Beta for high focus and concentration; Theta for meditation, insight and memory; Delta for deep sleep and healing; and Gamma to increase cognition and improve IQ.

In simplest form, they are an audio technology which are used for (safe) brainwave entrainment. Our subconscious mind operates, throughout the day and night, in various brainwave state frequencies, measured in cycles per second (Hz) These frequencies range from the slowest (Delta) frequencies experienced in deep, dreamless sleep and in deep meditation where your conscious-awareness is fully detached, to the fastest (Gamma) frequencies associated to stimulating flow states, high-level thinking and information processing. There are actually 5 known brainwave state frequencies each having their own set of unique characteristics:

Theta waves have a frequency between 4 and 7.5 hertz, making them slower than more wakeful alpha but faster than the dreamless slumber of delta. Theta brainwaves are the frequencies of nighttime dreams and REM sleep when the brain goes through bursts of activity and eye movement. People also experience theta waves in a state of light sleep, deep relaxation, during meditation and prayer, and when daydreaming. Theta waves produce an experience of inward wakefulness where we become disengaged from the outside world while engaging in inner activity. At the lower frequencies of theta, sleeping states are experienced, and at the higher range of frequency, awake relaxed states are experienced. 
Biofeedback enhancement: In 1981, researcher Arturo Manns discovered that 15 minutes of stimulation with isochronic tones enhanced biofeedback protocols for bruxism (grinding of teeth). They did this by increasing muscle relaxation superior than standalone biofeedback. Brainwave entrainment is different from biofeedback in that it does not allow the person to consciously control their brainwave state.
This music encourages a state of delta relaxation. Delta brainwaves are most prevalent during deep, dreamless sleep. The delta state is a mostly unconscious state that is essential to one’s physical, emotional, psychological and spiritual wellbeing. People who are able to achieve a state of delta relaxation through meditation will sometimes describe spiritual encounters and out of body experiences. The delta state is perfect for inducing profound spiritual experiences, healing and deep subconscious repatterning. Delta frequency brainwave entrainment music is also a fantastic cure for insomnia.
Thanks for your compliment on my article. 🙂 There are some frequency lists which reference and quote some links to metabolism, but I don’t know how effective or reliable that information is. One of the good things but also a drawback of this technology is how accessible it is to use and create tracks. That makes it unattractive for big companies to invest in large-scale research because it’s hard to patent and protect any product they produce based on the research. As soon as they released the frequency data, people like me would produce free videos and cheap MP3s to utilise the research, so they wouldn’t be able to get a good return on their research investment. So to try and gain some insight into what is working for people, at the moment, we are relying upon assessing anecdotal feedback in many areas. Before buying any products/tracks for increasing metabolism, I would look for and try out free videos on YouTube first, to try and gauge how those particular tracks and frequencies work for you.

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Entrainment is a term originally derived from complex systems theory, and denotes the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in a context and at a proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force, such that they adjust until both oscillate with the same frequency. Examples include the mechanical entrainment or cyclic synchronization of two electric clothes dryers placed in close proximity, and the biological entrainment evident in the synchronized illumination of fireflies.[13]