dupeGuru - dupeGuru is a tool for finding duplicate files on your computer.
Tune Sweeper - Show duplicates in your Music library. Automatically select which duplicates to keep and delete based on your preferences. Remove duplicates with one-click from your iTunes or Music app library.
Duplicate Cleaner - Duplicate Cleaner: the fastest and most popular tool for finding duplicate files. Over 1 million downloads: Get your copy now! Free and Pro versions available.
Dupe Eliminator for iTunes - iOS, iPad, iPhone, iPod Touch, iTunes, iTunes software, Software for iTunes, mobile iOS apps for iPad, iPhone and iPod Touch. Remove iTunes duplicates. Stream iTunes Music Library. Super iTunes Suite of useful tools.
AllDup - AllDup is a freeware tool for searching and removing file duplicates on your Windows computer.
iTunes Duplicate Song Manager - iTunes Duplicate Song Manager with Folder Watch removes iTunes duplicates in Windows and Mac OS X.