eCurrency Currency Converter
Price: $.99; Developer: Hendrick Holtmann
When traveling internationally, managing foreign currency means having to figure out how much you're spending in U.S. dollars anytime you make a purchase. eCurrency Converter is one of many iPhone/iPad apps that allow you to instantly perform currency conversion calculations.
This particular app supports 190 different currencies and uses up-to-the-minute rates provided by the European Central Bank (as well as other sources). However, to avoid international data roaming charges on your iPhone, you can update exchange rates before you leave. By entering the exchange rate manually when visiting a particular country, you can take into account any currency exchange fees you paid.
The calculator-like on-screen interface (shown in Figure 1) is easy to navigate, and most of this app's functionality is available from a single screen. Once you set your home currency, the app remembers your configuration.
So if you're visiting London, you can set the app to convert U.S. dollars to Euros once, and then each subsequent time you access the app, that setting will remain the default until you change it. A separate screen allows you to monitor multiple currency exchange rates.