Silent Sniper is en eBay automatic bidding application. To "snipe" is to bid on an auction at the last possible moment, so that the other bids don't have time to react and bid back. It is a common practice these days, and it can sometimes work if you are smart enough. This application does most of the work for you. When you have found something that you would want to bid on, you can simply click on the "Add auction" button, which will add it onto your list of auctions within the application. After that, you have to add a new snipe and set some options. For example, you have to tell the app when to snipe. To do this you tell it how many days, hours, minutes and seconds before the end of the auction you want the application to bid. You can also set how many items you want to buy (if more than 1 were available) and your bid. After you have changed those settings, the app should take care of the rest and place your bid for you when the time is right.
As I mentioned, this app alone won't win auctions for you. There are other variables to be taken into consideration, like prices, the time the auction ends, etc. If you snipe an item that is currently $10 and your max bid is $11, chances are that other eBayers will beat you.
I wasn't able to test the app's snipping features on eBay, because I didn't really want to buy anything. But you are given a 14-day trial to test this app before you buy it.