Currently, when cards are located on an app in app studio, that is not listed in the "Move or Copy Card" menu as a current location. For example, I have a card located on an app and also in my 'Overview', but the menu only shows my 'Overview' page as one of the card's current locations (see below). I am also not able to select an app from the list to move a card there manually.
This makes it harder to manage the locations of cards and keep track of what is where. Currently, the only way that I'm able to check if a card is being used in an app is to open that app and check the cards individually. Ideally, the app page would be listed as a location for the card or there could be a separate menu for app locations that allows you to move or copy cards to specific app pages.