AucSum is a tiny adjustment to the Auction House, it will add the total value of your actions to the bottom label, that normally only tells you how many items you have listed. With AucSum also the total value is added.
AucSum is compatible with Blizzard Auction UI and Auctioneer, others are untested.
Note:
If you cannot see the bottom label, you need to put more items on AH for it to activate. Once it's activated AucSum will automatically add the total value.