iCurrency Plus
Adding a New Pair
After pressing the add button, this screen shows up. Here you need to define the two currencies you want to track. Those currencies will be added as a pair to the currency list once you save your settings. If by any chance you make a mistake in the order of the currencies, a handy button has been placed there to swap them.
Specific to this application, and in this application only, you can track changes that occurred in time to a particular currency pair. You can define the period of time to check and what percentage change will trigger a notification. By default, the notifications are shown in the currency pair list with an arrow indicating a change in that currency over the period of time specified.
Also available in this application only, you can get notified via a push when a change greater than the specified percentage had happen in a period of time. That important notification that you are waiting, will be given to you even when your phone is off or the application is not running.