You can exchange between USD, GBP, EUR, PLN, CHF, DKK, NOK, SEK, RON, SGD, HKD, AUD, NZD, TRY, ILS, AED, CAD, HUF, JPY, MAD, CZK, QAR, THB, ZAR, MXN, RUB, SAR, HRK, BGN in the Exchange section of the app. The top half of the page represents the currency you will exchange from, and the bottom half represents the currency you will receive. Select currencies that you would like to exchange from the drop-down list.
Just enter the amount of money you would like to exchange on the top and the amount you will receive will appear in the box below. Click exchange, and that's it - your balance will be updated.