https://play.google.com/store/apps/d....brainwaveaday

I haven't tried the app yet, but I have downloaded it and installed it on my phone. I can personally vouch for the company that produces this software, though, as I've been a customer for many years.

I don't know how long the app will be free, so if you're interested, I urge you to give it a go as soon as you can.