AppViz charts all your app store sales reports for you, and for a huge time saving it logs in to iTunes Connect for you and downloads them automatically. An added bonus (assuming you can stomach reading them) is that AppViz will download all your app reviews too! AppViz charts new downloads, upgrade downloads, all downloads, and sales revenue. Graphs can be plotted by different date ranges and for different countries, and it converts everything to your own currency. AppViz doesn't currently support multiple iTunes Connect accounts, but there are work-arounds and the feature will be added soon. I'd like to see it handle the financial reports a bit differently to make it easier to reconcile with payments from Apple. Highly recommended.
AppSales Mobile is similar to AppViz, but its for your iPhone! AppSales source code is in Google Code right now, download with SVN and pop it on your phone with a debug build. Great distribution model for us developers! It's a fantastically designed app, squeezing lots of charts onto the phone without anything ever look squeezed. Charts and reports show daily or weekly sales revenue with drill down by product or country. AppSales does have one big drawback, it is oriented around revenue from paid apps. It will show download number for free apps mixed in with the overall report data, but it doesn't include downloads in the line graphs, they are revenue only. (Back in the day I used to use AppSales for the mac, but it's no longer being distributed or updated.)
My App Sales is another sales stats checker for your iPhone, but unlike AppSales it reports and charts both free and paid apps. Reports are broken down by day and week, with your account totals and app by app too, showing new downloads, update downloads, refunds, and sales revenue for paid apps. From the reports screen you can drill down to see that data country by country. The app will chart your data by sales revenue or downloads by day or week. My App Sales is the work of Oliver Drobnik, and he's still maintaining and actively marketing the app.
MajicRank and AppRanking scan iTunes servers and figure out apps ranking in iTunes stores around the world. As well as top 100 free and top 100 paid, the app stores have top 100 free and paid for each app category and game sub category, all of which can be browsed on the app store available on the iPhone and Touch themselves. I was very surprised to learn that Hit Tennis is in the top 100 paid sports games even in many countries including the USA, and its even in the top 100 paid games in a few countries around the world. This is really encouraging, and moves up the next release of Hit Tennis in my priorities. MajicRank is the first of the sales stats tools to record ranking data over time and graph it. Graphing ranking data alongside sales data and your calendar of marketing actions is very powerful for understanding how to tune your marketing plans to make the most from your apps. If you're not sure about what all the different ranking lists are, read: app store top 100 rankings explained.
Mobclix shows app rankings on their site, with graphs. They are charting top 100 popularity free and paid combined, for the USA app store (so their numbers won't match MajicRank's numbers). Go Imangi!
AppStore Clerk is a simple utility that parses daily and weekly download reports and shows you the data in an easy to read table, showing new downloads and updates.
Heartbeat is a fully featured subscription website that features everything in all the tools above mixed with crash reporting, analytics, and a whole lot more. When I sell my millionth app I'll try it :-).
AppStatz is another online solution to check out, though it's still in private beta. (thanks @shanev). AppStatz - let me in your beta :-)
Drop me a line and tell me about the tools you use.