Eve Commander is a third party website for Eve pilots which takes the API keys for your characters and displays a lot of relevant data on an out of game website. UPDATE: For full disclosure I am using the partner program URL for the link above so I get some ISK for each full registration that uses de503954 as the personal partner key on the registration form.
What's really neat about this tool is that it allows you to see what ships are equipped with and in what station, something you can't do in game even!
You can also browse your wallet journal, transactions, market orders, and your complete list of assets including what is in containers in far off stations (again, something you cannot do in game).
You can't change anything in game from here, but seeing all your assets, ships, market orders, and skills in one place is truly impressive.
Its not free. Depending on how rich you are determines how much you pay per month to use this amazing tool. I find that kind of regressive and a cagey player might simply store his ISK in a corporate wallet or an alt's account, but the monthly cost is not overwhelming even at the maximum fee of 8 million ISK.
UPDATE: It was pointed out to me that the cost is per 90 days, not 30. This is a marvellous deal in that case as I was willing to pay 3 times as much for the service.
Also, the line "I find that kind of regressive" is confusing: I merely meant that the insanely rich (i.e. billions in wallet) benefit greater than the sort of rich (~500 million ISK). Its not a slam so much as an observation.
As the screenshot shows, there is no automatic subscription so your money is safe.
I'm currently running the trial account for my two mains but will definitely upgrade to full edition for one character at least, maybe both. The effort put into this tool (which looks to be continuing with more features on the way) is impressive and I look forward to the usefulness it will provide me, especially when looking for that rare module I thought I still had.
Note: There is a corporate subscription model but it was far to rich for my little indy's corp's blood.