Fugue - Free and premium stock music for your videos, games, and UI
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.
UI Sound Kit 2 - A new pack of 130 clean and neat UI sounds for app makers
Noizio - Feeling that the noise of the big city is too much for you to bear?
Soundkit - Professional sound effects library designed for UI projects
MyNoise - Custom shaped online noise machines. Many Many generic sounds