Try the MuseMonitor app. It is available for iOS, not sure about Android. MuseMonitor shows real-time graphics of alpha, beta, gamma, delta and theta waves. There is no audio. But I have meditated while viewing the MuseMonitor graphics. I keep my eyes slightly open, just enough to see the lines for the different brain waves, which are in different colors. I place the iPhone on one of my thighs near the knee. It would be a simple matter to attach the iPhone to a tripod positioned comfortably in front of my face.
So far, I have been able to easily increase amplitude of the alpha waves, according to the graphics. After a few minutes of focusing on my breath and calming my mind and body, the alpha will increase, moving toward the top of the graph, and the other waves will decrease, clustering together toward the bottom. The separation between alpha and the other waves is even more enhanced as I begin to see nimitta, light artifacts indicative of access concentration.
I’ve also tried meditating with Muse and the MuseMonitor while listening to Indian Classical Music, ragas. There is the increase in alpha, but the other waves do not decrease and cluster toward the bottom of the graph as much as in meditating without the music. Also, interestingly, the moment-to-moment increase/fall in alpha seems to track pretty well with the ragas, rising and falling with the music!