I found this as a free app on my iPad and I love it. I have three that I downloaded and this one is the best, in my opinion. It has 6 already set theme combinations for quick enjoyment. A Beach, Campfire Night, Lake, Bird Garden, Musical Waterfall, and Rain. Each of the 6 theme combination comes with a beautiful picture for screen. These are nice, but I like to make my own combinations, here is a list of sounds on free version.
Loons on the lake
I have used this App in many ways for myself and the kids. When reading I can have the app open and be in other sites, ibook, anywhere really. The other two app's close if you leave the screen so you can't be multitasking and listening at the same time. I use it while I do my Yoga, cooking, reading before bed, at doctor offices, pretty much anywhere I want to be relaxing with my Rain and Storms. The kids love to make their own combinations that they find relaxing.
The app has features for timers wake up, fade out, sleep, and more.
Relaxing Nature Scenes (helps to relax, meditate, sleep and yoga) By Red Hammer Software