Simple addon that allows you to sell all your trash items (gray) to a vendor. Simply open up a vendor window and all your trash will be sold, giving you the total amount of the items sold.
Very useful to save you time managing those useless items in your bags.
If you're interested, I have also created an addon to toggle your minimap: https://mods.curse.com/addons/wow/toggle-mini-map and another one to toggle your quest tracker: https://mods.curse.com/addons/wow/toggle-quest-tracker. Very useful to save up some space.