How to Recognize Unused Apps Immediately
For some time now, Apple has released much more information on app usage and will continue to expand it in iOS 12. Until then, however, we have to be content with a smaller scale. To do this, open the settings on your iPhone or iPad and tap on "General> iPhone Memory" (or "iPad Memory").
Now wait a moment for your device to gather all the information. In addition to the storage space usage and distribution to different categories (Apps, Media, iCloud Drive and others), you will see all installed apps sorted according to memory requirements in descending order. Under each app is also the note "Recently used:". For some applications, you will certainly read "Never used". If such an unused app uses a lot of memory, you may want to consider removing the app from your device.
Remove Unused Apps
Apple has included two ways to remove or temporarily delete apps that are either unused or unused. To do so, tap an app under Settings> General> iPhone storage (or iPad storage). You will now see information such as version number, developer, size, data, etc. At the bottom you can delete the "App" without leaving the menu. Alternatively, you can also outsource the app. This will also remove the app from the iOS device, but the associated memory data will remain on the device and can be reused after a re-installation.