Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.
Sleepy Baby - Help your baby sleep with the Sleepy Baby soundboard.
Noizio - Feeling that the noise of the big city is too much for you to bear?
Power Nap App - Best napping timer with relaxing sleep sounds
zenmix.io - Ambient background sound generator
Drift Sleep App - Sleep to the sounds of different locations around the world