Unfortunately, I have not yet been able to find a safe/stable/reliable/portable/cheap EEG device that I can link to my own app - otherwise complete feedback and control of the entrainment signal would be in the next release
why not build one?
Development of arduino based low cost neuro-feedback applied to ADHD, Enas Abdulhay, Arwa Abdelhay, Aya Kilani, Lana Al-Shwiat, Salam Al-Rousan
changing the arduino for an ESP8266 for wifi/portability
whole thing would cost less than the pack of electrodes and have medical accuracy