Duper is duplicate finder designed for Mac. This utility comes in handy if you're dealing with a large collection of images, songs or videos and wish to get rid of all unnecessary identical files with just a few clicks.
You don't need much computer experience in order to handle this program. All you need to do is select the folders you wish to scan and the program will do the rest. It also features some advanced scanning options (MD5 cache, optimized MD5 implementation, minimum file size, etc.).
Once the scanning process is complete, the application displays a list with all found duplicates, nicely sorted into groups. You can then select the file duplicates you wish to delete from your Mac. The program immediately erases the chosen documents without slowing down your computer.
Unfortunately, the app doesn't work 100% as nothing happens when you click the About and Preferences buttons. Another disadvantage is the fact that you cannot preview or pre-listen the found duplicates. So, you can't be 100% sure you're deleting the correct documents.
In my opinion, you should look for other duplicate finders as the aforementioned flaws are pretty important.