I used the above code.

The app is a compelling idea -- incorporating both current exchange rate and foreign-transaction fees. I think it could be very useful, especially when you can't/don't use a fee-free card. However, its database of US-issued cards is limited (i.e., few/no co-branded cards), and adding new cards is very buggy (e.g., the "Bank" and "Min Withdrawal" fields seem to be wired to the same property).