How to add, remove, edit a credit card?

Go to the Menu button (☰) on the top right of your screen,
Click "Accounts & Cards", make sure that you are in the "Money In" tab.
To add a credit/debit card, press the + sign
To remove a card, press the pencil icon found on each of the cards, then click "remove".
To edit information on a credit/debit card, you must remove it first then add it again with the correct information.