Source: http://lifehacker.com/5592227/simplynoise-now-features-sleep-timer-and-ios-app
Two years ago we featured SimplyNoise, a dead-simple white noise generator. A recent update adds in additional sounds, features, and an iOS app for white-noise naps on the go.
Originally SimplyNoise did one thing: play an endless loop of white noise at your preferred volume. The site overhaul introduces several new and useful features. You can now select from white noise, pink noise, and brown noise. Which sound, respectively, like radio static, ocean waves, and airplane droning. You can set them to oscillate—pink noise on oscillation sounds like perfectly time waves crashing—and a new sleep timer makes it easy to fade out the sound after you've dozed off or to set an end time for your power nap.
If you want to take the new features with you SimplyNoise is available as a $0.99 iOS application. Otherwise, the site is free and requires no registration for use. Check out the site below to sample the random noise generator or listen to—and download for free—their featured soundscapes. The current offering is an hour long thunderstorm track. Have a favorite site for the perfect power nap soundtrack? Let's hear about it in the comments.