Get a report of your device use on iPhone
When you have Screen Time set up, you can get a report of your device use.
Go to Settings > Screen Time.
Do one of the following:
Tap See All Activity to see a summary of your weekly use.
Tap Day to see a summary of your daily use.
You can also view your summary by tapping a Screen Time Weekly Report notification when it appears on your screen. (If the notification disappears, you can find it in Notification Center. Alternatively, you can add a widget for Screen Time to Today View.)