Highlights "On Sale" Products
A special badge (label) is added to the discounted products' thumbnails. This will highlight the products that are on sale from the total mass of items in product listings.
Moves up promotional items
All the products that are sold at a discount will be moved to the top of the category. In this case, you visitors will always notice that products and more likely buy them.
Creates Sale category
The plugin adds a separate "Sale" category. All the products that are on sale will be automatically displayed in this category. Layered navigation and filtering will work fine there.