1)   Remove Duplicates from Excel 1.1.4
The add-on is designed for searching and processing duplicates in Excel tables. Program key functions: a search across rows or columns; search across an entire table or a specified range of cells; an opportunity to compare by values or formulas.

 2)   DeDupe 1.6.4
DeDupe is a duplicate file finder that deletes duplicate file from the hard disk. It finds and removes duplicate files safely.