I thought it would be fun to have a card collecting add on.
It would have a GUI that showed the cards. And when a player connects it would add their card to your collection if they have the CC add on. And there should be a way to collect more than one of the same ID and you can trade cards by using the GUI. Also the GUI should have a card creator added in so that when people get the add on they can upload a screenshot from their blockland folder that they want as their card picture. I made an example card.