eBay Auction Sniper and Auto Search is an eBay snipper. It also comes with a built-in browser that allows you to browse eBay.com or any other website from within the application. The application divides both features by using a tabbed interface. The two available tabs are "PowerSnipe", from where you add snipes and "Auction Browser", the built-in browser.
This application is free to download, but you will need to sign up for an account with Powersnipe.com to actually use its snipping capabilities. It is unclear to me whether the client application does the snipping or if it is done on the server. It looks like you can follow current snipes on the website if you log in there, so that makes sense.
To start a snipe, you first have to find an auction and then click on the "snipe" button, which will prompt you about a few details that need to be filled in. You have to tell the application how much you want to pay for the item. If you sign up for an account, you get additional features, like e-mail alerts and daily auto-search.