This program is good especially for those who need to study or work from home. I'm rating the Mac version as a 4 because I have the free version on the iPhone and it's obviously the expanded version that was on the Mac previously. The iPhone version is a 5. When you intentionally downgrade an app, you're going to get lower evaluations.I use this app with a set of headphones and love it because it allows me to concentrate on my work. I couldn't ask for much more than that. Just put some, if not all of, the other sounds back into the Mac app and be done with it. Your customer service rating will go up - and isn't that what you are really concerned about?KF

Works on a wide range of OS versions has a nice set of sounds; price for more sounds is not high either. Quality of the sound is excellent. App design is excellent including how it animates to show you were the app is located -- likely something that was added after the bad reviewers didn't notice where the app resides. For FREE this is the best app. It is not overblown and does it's job well; hopefully it doesn't end up with too many features which detract from it's purpose. I will probably buy the pay version I am just waiting for some months to see if the app has any quirks that cause troubles.The one thing I would like to see is a setting to have it stop when the display goes to sleep (instead of just times) so that it isn't running all day while the monitor sleeps.

Does what it's supposed to do and well

The app never opened, but left a sound of waves that wouldn't stop until I restarted the computer.