Android users can select the bank card option from within the Yolla app. Just open the side menu of the app, choose "Add Credit" and follow the on-screen instructions to choose a top-up amount and payment option.
iOS users can use a debit/credit card on our website https://yollacalls.com/en/account/, which they’ll then be able to use on further top-ups from within the Yolla app and avoid paying the Apple commission. 👍