If you are using CBT to deal with your mood, consider this app: Moodnotes: a Thought Journal, Mood Diary, CBT App.
It helps you quickly capture your mood, but it also help you deal with distorted thinking that contributes to poor moods or worse.
I am cautious about recommending such apps, because I worry what the app developers will do with the data. I have looked at their privacy policy and it is easy to understand and it says they won’t keep specific data. So I am cautiously recommending it.
Smart People I Know 