Just enter the base directory and the app will search for files with the same MD5 hash. These are considered the same. You can select versions, display and delete them.
The original app is more than ten years old. It aged in a private repo, but one day I thought it might be useful for others. So I made it available to the public. The new user interface is using Compose for Desktop. But the old Swing version is still there and functioning, too.