As an eBay seller, you are supposed to leave feedback for your buyers. As any experienced eBay seller would tell you, leaving feedback while important can take significant time particularly if you have a large number of buyers. In WonderLister which is the best 3rd party eBay listing tools, you can automate this process 100%. Once you have setup your preferences for leaving automatic feedback on eBay, WonderLister will do the rest, without needing any intervention from your side.
*** This feature is unique to WonderLister and is not available on eBay itself ***