From the README.txt:
The price of a product might change in different currencies by a value not
determined by it's actual rate. For example 1USD might be 100YEN in one
product, but 150YEN in another.
The module alters the price according to the user's currency.
The currency information is set in a cookie for authenticated users or in the
session for anonymous users.
* It seems to be working already, however I've set it to 'Uploaded for testing' until after moderation.