Category - Money mod
Necessity Level - Low
Class/Role - Any
There are some addons I've used for such a long time I forget what they do. Auditor is such an addon, so I had to ask Love. It's always just been around, sitting in the corner (or on my Chocolate Bar more recently), doing its thing so smoothly I even forgot it was doing it. It's funny when you get so used to some features you think they're actually part of the game and then you freak when you happen to play on some friends computer without addons.
It doesn't really do anything necessary, it's more one of those neat to have addons. Auditor will give you a better overview of your cash flow, showing for instance where your money is coming from and going to. It will also show you how much money you have on alts and how much you've earned or spent this week (or another time frame) and on what. (Image borrowed from Curse.com)
If you're one of them AH-nerds, constantly sitting around trying to make a buck, being able to keep an eagle eye on earnings and outgoings is quite nice. I use it mainly to keep track on how much money I have on alts, but considering I have another addon that does that as well... Well, Auditor does it in a really easy-to-view way and since it doesn't take much space I might as well keep it around, like I have all this time.
Auditor can get really specific, showing you for instance how much money you spent the last week/day/lifetime etc on stuff like repairs, vendors, AH etc. You can choose to look at a specific character, realm or overall. So if you're one of those people who love addons because they help you keep track on everything, then this is definitely for you. There is even an option called "Absurd Detail" and that is really what this addon is all about. There are really no drawbacks about this addon, if you want to know everything about your money flows, this will do it for you. And then of course if you're not so interested in that then there's no need for you to use an addon like this. It won't make you a better player, it might however save you some time when you're trying to buy something expensive on your alt and are unsure about if they can afford it or if you have to send them some money.
It hasn't been updated for quite a while, but still works well for me. I only use it very little though. The creator also tells us that Spicy Meatballs is part of the "new features", can't miss out on that can we!
And you can find it here.