I got this app a few minutes ago, while it was free. Expecting a gentle, soothing sound, I turned it on and got the sound of rushing water. My husband, in another room, thought we had a broken water pipe! The sound was extremely annoying. If there are other sounds, I wouldnt know, because I was desperate to shut it off. I couldnt put it in the trash because it was open. There was no choice in the right click to quit, just to open. I couldnt use the keyboard to quit or force quit. It didnt show up in the list of open applications for force quitting! I rebooted my Mac. Phew! It was then closed, so I trashed it.
Hoping to save others from this, I found Chill in the Mac Store, but it now costs $2.99. I see that there are now instructions about turning Chill off. Good. But I wouldnt try it again, even if it was free.