I purchased this app about 16 months ago and have used various sound tracks for pain relief, anxiety suppression, insomnia, mood elevation, concentration enhancement and various other benefits. It is extraordinarily effective and its benefits rapidly take hold with my Bose over-ear headset. It benefits are truly remarkable and even continue after I must power down the app, say when entering a work situation. If you need relief, motivation, focus or any number of other benefits you cannot go wrong with this unmatched app.