Expert Cleaner is a utility for cleaning the phone's storage. It analyzes and removes duplicate and unnecessary files to free up space. 

Once you launch the app, you'll be prompted with the main window. Here you can see all the files and folders on your device.

After that, it will detect all the duplicate files and photos and show you all of them. If you want to delete any of them, just select the ones you want and click the delete button.

If you want to know more about the app, you can go to the developer page