Duplicate File Finder 

com.nektony.duplicates-finder

Publisher Description:
Get more free disk space by removing unnecessary duplicate files and folders from your Mac. Remove duplicate files on any mounted disk or folder.
Use Duplicate File Finder FREE to find and remove duplicate files. Get the PRO version to delete duplicate folders, merge similar folders, mass select duplicates and more.

Get rid of duplicate files just in 3 steps:
Scan a disk or folder for duplicates -> Select duplicates -> Review and Remove duplicates.

In a few minutes, Duplicate File Finder will provide you with a report of all the duplicate files by their categories: pictures, videos, music, archives, documents, and any other specific extensions. It has never been easier to see how much space each file takes.
With Duplicate File Finder Finder, you can scan as many folders as you wish. All you need to do is Drag and Drop the folders or disks into the app and click the Scan button.

List of the best Duplicate File Finder features:

SCANNING
fast scanning algorithm
ability to scan for duplicates in multiple folders and drives simultaneously
support for external drives and mounted network folders
"Recent Folders List" for scanned folders
animated scanning process
skip list for various files and folders
"minimal file size" option for a faster scan

RESULTS OVERVIEW
visual chart report when scanning
duplicate files list
duplicate files by type

DUPLICATES
built-in duplicates search
preview duplicate files with Quick Look
sort duplicates: by name, size, date, total size, type, duplicates count

SELECTING
one-click selection of multiple duplicate files
"always select" and "never select" auto-select rules
smart duplicate auto-selection
option to mass select duplicates in particular folders using Select Duplicates in Folder feature
reverse selection with "Keep files..."
visual progress bar of the selected duplicates

REMOVING
confirmation list of files being removed
customizable view of confirmation list
customizable removal options: move to directly Trash, remove completely, or move to a specific folder
history of removed duplicates
ability to restore removed duplicates

Duplicate File Finder FREE application allows you to: