Just what I was looking for. The beauty of it is that you can solve for any one of the four variables (loan amount, interest rate, number of monthly payments, monthly payment) by inputing the values for the other three. It also shows a detailed payment schedule. Definitely worth the $1.99.

This really is a nice program - one of the few calculators that allows solving for any variable (Principal, Interest Rate, Duration, AND PAYMENT). It also has a good amortization table (monthly and grouped by year). I first tried it on my iPad and had an immediate problem: In the calculator mode (where you enter data) the keypad that pops up doesn't have a key for the decimal point. For example, I wanted to enter an interest rate of 5.375, but I couldn't enter the decimal - so I got 5375. There is just no way to do it. So I tried the program on my iPad Touch and the pop up keyboard has a decimal point. The program worked perfectly. I don't know where the bug is, but if you have an iPad you will probably experience this problem.I would offer one suggestion: It would be nice if you could enter an "extra" amount to pay each month, so you could "what if" the loan. Other than this suggestion (and, of course, the iPad problem) - I'd certainly recommend this program.UPDATE;I updated my iTouch to OS4 and I now have the same problem with it as I do with my iPad. You cannot enter an interest rate that contains a decimal point. That makes this program basically useless because most allInterest rates have a decimal point. I would NOT recommend this program.