I use this app daily for several reasons. One of which is to manage panic attacks. This is an epidemic among people from ALL walks of life. If you or someone you know suffers from anxiety disorder(s), PLEASE refer them to this app and learn how to use it effectively.
The only con I found was that the ambient music/sounds are way too short. You can clearly tell when a track ends and when it repeats. As a producer, I would say you could probably get away with better editing/looping as a quick fix. Or, get longer tracks making the breaks spread out. But the ultimate would be to talk to Dan Gibson of the famous "Solitudes" CD library and talk partnering or licensing.
Dr Talk about BrainWave: 37 Binaural Series™, v6.1