Sleep as Android - Common alarm clocks ignore your sleep cycles, they wake you on schedule no matter your are currently in your deep sleep. Waking up from deep sleep is unpleasant, it makes you tired and it may negatively affect your productivity during the whole day.
Defonic - Create a unique sound environment at home or in the office
Sleepedy - Personal sleep coaching & therapy
Noizio - Feeling that the noise of the big city is too much for you to bear?
Pzizz - Sleep at the push of a button! Now with "Focus"
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.