Do not recommend. The Crown didn't operate as implied on the website. There is an image on the home page of their website which shows a User's graph when they have been tracking their brain waves while working for over 2 hours, however it's not possible to do this with the app and device that I have. The supplied app (with prioprietary music) only works for 5 minutes at a time and you're meant to stop what you're doing, close your eyes and focus on the music while it's playing ie. you cannot use it continuously while you work. The manufacturers suggest you can you link it with a Spotify premium account but this is just playing publically available music and I can see no way to monitor what my brain waves are doing during those sessions.
terrible do not buy they charge $200 restocking for returns and expect you to cover deliver fee. Device itself does not work well with the app. I used for 20 mins and only scored an increase in 5% of focus. During other sessions I did not even feel a difference in focus overpriced. Takes a while to get a response from the customer service also