Duplicated files are more than just annoying — they can also eat up valuable space on your hard drive. Twins  can locate, and then delete unneeded duplicates including files as well as software programs. After dragging the folders that you want scanned into the app, it generates a list of duplicates, which you can review before selecting files for the trash. Twins even tells you how large the file is, keeping a running total of how much new hard drive space you’ve scored. Available on the Mac App Store, Twins is priced at $9.99, but is selling at a 70% discount of $2.99 — a perfect price for a little fall cleaning.