AppTime

AppTime tracks screen time - time you were reading news, messaging, playing games. The times are recorded per app. Historical data may be recalled by date or viewed as a chart. A widget on the home screen shows total time spent with the phone or tablet today.

From "Date last used' screen you can see when last time you've used an app or if you have used it at all recently. It is easy then to free space and uninstall all unused apps at the same time in a batch mode.