Binaural Beats stimulates your brain by sending special auditory artifacts directly into your headphones to produce subtle changes in behavior through entrainment of brainwaves frequency. Brain activity operates in waves whose frequency can be encouraged to change by the sound waves produced in the app. This app claims to help induce relaxation, creativity and many other desirable mental states. The app automatically pauses and resume if a phone call arrives. This is why PHONE_STATE permissions