dupGuru actually looks at the actual content of the files on your Mac instead of the filenames to find duplicates. This has helped me! I have a number of files that, for various reasons, have altered file names but remain the same file and I don’t need duplicate files on my machine! Tools that save you time is what computing is about! (Though you could also say that the computer created all these duplicate files in the first place and the mess that this causes stole some time of my life away but that’s another story and overall, computers are a time-saving tool when properly wielded!
It looks like it’s also available for PC and Linux too.