Amateur, annoying UI, sounds and visuals.
I have been trying a few apps with my neurosky mind wave. I found this one to be poor and not conducive to relaxation or clarity. The sound effects are poorly recorded with background noise, they are jarring and unpleasant (specially when you're trying to clear your mind). There are much better apps for the same price in my opinion. Should have known, seeing as it doesn't appear to be maintained proactively.