Support for All ISO currencies is included with app and every part of solution is designed to support any currency without any customization.
The currency is to be assigned to regions app work on. When defining region and drawing it on the map there is a select field that you can use to select your regions currency and this will be effective throughout system accordingly without any customization needed.
All app wallets & Financial reports are designed for multi currency.
When a region is defined you can no longer edit it's currency. This is to prevent data anomaly. So choose the currency correctly first time.