Just need a simple currency calculator to track currency rate? Take a look at xCurrency, the currency exchange app may suit for you.
The xCurrency is a simple yet powerful currency calculator app for iPhone. The iPhone app features an intuitive and minimal user interface, and comes with more than 140 kinds of world currencies, moreover, the currency calculator app can show you four different currency exchange results, while simply swiping the screen allows you to change currency, and its calculator lets you easily input digits.
xCurrency is available for free at present. If you need it, head to App Store for download.