FitMind - Mental fitness & meditation training
Brain.fm - Music designed for the brain to enhance focus, relaxation, meditation, naps and sleep within 10 - 15 minutes of use.
Headspace - Meditation made simple. Brilliant things happen in calm minds.
Soundlove.io - Choose and mix from 100+ high-quality sounds and noises to improve focus or relax.
Calm - Take a break and meditate.
Moody Music - Focus, relax, & sleep musics