You can edit the information of a card in your collection while using the app. This is useful for updating a card's information on the go.
To edit a card, go to your collection and find the card you wish to edit. Tap the card to open it's details and then tap the pencil icon in the top right corner. You will now be able to:
change whether the card is foil or not
change the card's condition
add or remove tags
remove the card from your collection
Make sure to tap the save button in the top right to save your changes.