Brain.fm - Music designed for the brain to enhance focus, relaxation, meditation, naps and sleep within 10 - 15 minutes of use.
moooodify - Sort your Spotify music by any mood you like and save them as playlists.
Music Time for Spotify - Discover the best music for coding with data and Spotify
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.
Zenisounds - Zenisounds is an online platform that lets you mix ambient noises to create the ultimate relaxation playlist for free.
Deepwork.fm - Minimalistic "radio" with 4 channels