By default application shows major currencies in the list. You can modify this list of currencies by pressing "SELECT CURRENCIES" button on top/app menu. Press "SHOW SELECTED" to go back to main list.
Tap currency item (or flag) in list and enter amount to be converted.
Press On/Off button by side of currency flag to view/hide on list.
Select "Update rates" or "Update currency data" in app menu to sync data with the internet server.
Network connection is only needed when updating rates.