zenmix.io - Ambient background sound generator
Defonic - Create a unique sound environment at home or in the office
VirtOcean - Build your own unique ocean for relaxation or productivity.
SoundDrown - Ambient sounds to help you focus, relax, and escape
Ruya - A calming space
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.