It's a meditation app that mostly consists of calming sounds that you can mix and add together to make your own little calming background noise. I originally got it for sleep but now I've pretty much extended its use to all sorts of things, It helps me a lot.
It's got sounds like birds, crickets, wind, water, rain. It's even got things like musical sounds, dogs barking, even the refrigerator hum.
You'll have to get the extensions for more sounds (I just got all the free ones). It's a little confusing at first but not hard to figure out. It's a really nice app and it's free.