I have written several articles about financial applications or apps for the iPhone, including Top 8 FREE iPhone Apps for Investors. I even wrote about how to toss your cookies on your iPhone.
Although I've written about the Apple (AAPL) iPad Magician, I don't own an iPad. Therefore, I can't comment yet on the iPad apps. Fortunately, there is another site that has done a great analysis of the top 20 financial apps for the iPad. It has everything from spreadsheets to expense tracking to personal budgeting to stock tracking to oil, and gold pricing.
Author owns AAPL.