Daily Minded - The easy way to maintain a journal, diary or captain's log.
Headspace - Meditation made simple. Brilliant things happen in calm minds.
Mini Diary - Simple and secure journal app
Medito - 100% Free Meditation App that will improve your Mental wellbeing with the help of Guided Meditations, Breathing Exercises, Mindfulness Practices, Relaxing Sounds, and more.
Grid Diary - The simplest way to get started with keeping a diary
Calm - Calm.com can help you reduce stress and increase calm.