This app lets you check for correlations between your mood and sleep/exercise patterns.
You will be prompted to allow access of your sleeping and walking data from Health app. If you are not using Health app to track that data or you don't want to allow access, you can always enter those numbers manually for each date.
Every evening application will ask you how would you rate your day. (You can opt-in for push notifications. In that case it's easier, so that you would not forget making that entry)
All the data that app gathered will be presented in chart. So you can check if your sleeping time or walking patterns correlate with your mood.
FINALLY. Finally an app that just does what it says it’s going to do. No attempts to hog all my time with little rewards and incentives to come back each day. Just an app that respects my space and lets me maintain my own motivations for using it. You open the app, rate your mood on a scale of 1-10 and then you’re done! You can also include step or sleep data. Beautiful simple interface, data that any data cleaner would be proud of, and an app that doesn’t take up all my time doing one simple thing.