Umbrella is a prevention tool that reports the duplicates the moment they are created. Prevention is better than cure.:
Umbrella reports the duplicates the moment they are created. Forget the boring job of dealing with huge results when using a standard duplicate tool. Umbrella is the only duplicate-prevention tool available on the market. It is unobtrusive, easy to use, and powerful. Umbrella is a perfect Tidy Up 5 complement, and used together they will keep your Mac clean and efficient.

Features:
• Search in iTunes database.
• Search Photos image files.
• Search by files.
• Customize criteria to determine the duplicates.
• Automatic mark for a fast removal.
• Multiple files preview.
• Full integration with Tidy Up 5
• And many more.