SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
Headspace - Meditation made simple. Brilliant things happen in calm minds.
Sleep as Android - Common alarm clocks ignore your sleep cycles, they wake you on schedule no matter your are currently in your deep sleep. Waking up from deep sleep is unpleasant, it makes you tired and it may negatively affect your productivity during the whole day.
Being - See Instagram through the eyes of your favorite celebrities
Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
Plum Village - Free mindfulness app w/ Zen Buddhist meditations + teachings