Headspace - Meditation made simple. Brilliant things happen in calm minds.

Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.

Timeless | Meditation - Personal practice meditation timer with guided instruction and multi-day courses.

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.

Calm - Calm.com can help you reduce stress and increase calm.

Talalarmo - Minimalistic android alarm