Headspace - Meditation made simple. Brilliant things happen in calm minds.
Pzizz - Sleep at the push of a button! Now with "Focus"
Mindful Moments Reminder - Practice mindfulness during your day at your Mac
Sleep App - Relax, meditate & sleep
Calm - Calm.com can help you reduce stress and increase calm.
Pulse - Pulse is an application that downloads pictures from the internet and uses those images to automatically change your wallpaper.