Our Second role is to change the UI of the wallet.

Our wallet also needs to record the date and the exchange rate at that time (in the relative currency the user is using) and have a statement available for printing with variable parameters. "for the month of", "Last Week", "Last Month", "Previous 3 months" and so on.... This is for the record keeping of a users transactions, so they wont have problems complying to any tax they may wish to claim.