I have to wonder, sometimes, though. It seems like every other week there's a new invoice app out there. It's like a slightly more advanced version of the To-Do list tutorial app. I get that invoicing is a problem, but given the vast number of alternatives out there, aren't there more interesting problems to solve than Yet-Another-Invoice-App?

(Granted, here I am, typing away at Hacker News and working my day job and not creating anything useful for anyone other than my employer, but... a man can dream...)