Apple recently released iTunes Connect Mobile [Free - iTunes Link] which allows registered developers to track app sales and trends. The app is available via the App Store now and is a free download. For developers, this provides an extremely easy way to not only check sales numbers but to see trends on the go.
Simply log in and you'll get a nice layout that shows you not only your total sales but a breakdown of sales by application. From what I understand, you can see either daily or weekly totals as of right now. As we are currently working on applications and haven't released any yet, I don't see any breakdowns. Any developers have any feedback on the breakdown or things you'd like to see in an update?
I think another really neat app idea would be if Apple released an app that let regular users see purchased app histories and showed totals of all iPhone/iPad apps they've purchased, as well as a monthly breakdown of what they're buying. It would be interesting how much users spend on apps in total. After 3 years of using an iPhone, I'd be nervous to see how much I've actually spent on apps. Hit the break for some screenshots!