To get a full answer you should really get in touch with the owner of the app, because it does really depend on how their track is constructed and how they intend it to work. I have one 50-minute sleep track which takes you down into delta (http://www.mindamend.com/shop/sleeping-and-dreaming/sleep-induction-isochronic-tones/) and that is designed to just get you to sleep, so you just let play until the end. If you played that track on repeat it might make you jump and wake you up, as the track begins at a higher frequency. I have another 8-hour sleep track which is meant to be played all throughout the night (http://www.mindamend.com/shop/sleeping-and-dreaming/deep-sleep-8-hour-sleep-cycle/). So it does depend on the individual track you are using.
Robert Monroe, a radio producer and executive published a popular book called Journeys Out of the Body about his out-of-body experiences when using brainwave entrainment. He later founded an original brainwave entrainment audio company, Hemi Sync. In 1981, the book Mega Brain by Michael Hutchison brought brainwave entrainment information, techniques, and terminology into the popular press.
Depression: Currently there is no substantial evidence to support the idea that brainwave entrainment treats depression in adults. Some evidence goes as far as to suggest that the wrong entrainment protocol (e.g. slow wave stimulation) may actually increase certain measures of depression. Stimulation of delta and/or theta, will likely worsen the condition and alpha is unlikely to have an effect.
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.
a concise P.S. I was in a horrible car accident when I was 18 and had to learn to read and write and walk and talk all over again. It was long ago and I’m pretty well over it, but such an injury has lifetime repercussions. The neurological damage sustained causes my left arm to shake uncontrollably anytime I use it in a situation requiring precise coordination. From simply listening to the demo, the shake [though not disappearing completely in the last 2 months] has lessened dramatically. I had been wondering for years what kind of neurological exercises I could undergo to help it…
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.
Brainwave entrainment also happens with the use of pulsating light, and visual and auditory stimuli are sometimes combined for additional effect and visual stimuli is used alone. Using brainwave entrainment techniques is safe for almost everyone, the exception being pregnant women and people who have seizure disorders who should check with their physician before using these methods.
“Wow, wow, wow! When I coach people, the first thing I do is help them change their state as quickly as possible – and now it’s as easy as using one of the Brain Salon sessions. I can’t wait to share this program with all of my clients – once they use Brain Salon to easily get into a powerful state, then the work I do is going to take them to levels they never imagined possible…”