The widget makes full use of money.js and the Open Source Exchange Rates API, allowing it to dynamically grab the latest exchange rates, and substitute displayed prices in real-time. All prices formatted by WooCommerce are updated, even totals. Checkout still uses your store’s base currency, but the converted price is also stored for your reference.
You can add and convert to as many currencies as you want via the widget settings:
On the frontend:
Magic! As a bonus, the converted total is also stored when users check out, so you know what price they saw.