eBay Ends is an extension that installs an 'EE' at the bottom of your status bar and provides a display of the date and time of when your watched items and "current selling" items will expire.
The 'EE' indicator in the status bar shows you that the eBay Ends extension is active. Don't expect anything to happen right away. The eBay Ends extension will only kick in when you are on your "my eBay" page. If you have any items that you are watching or current items you are selling, there will be a new item under the "Time Left" column. A customizable date and time will display showing you the date of when the items will expire.
And no, it doesn't automatically count down. But, boy, wouldn't that be cool.
Overall, the extension was easy to install and the functionality is helpful enough. It's definitely easier to look at the date and time instead of clicking on the product and searching for when the auction will end.
Of course, since she's an avid eBay-er, I will probably be installing this for my wife.