You can check your Jokers in your album at any time. To use a Joker, tap on a missing 3-Star, 4-Star or 5-Star stamp in your collections and then select a Joker. For example, a 3-Star Joker can be used to add a missing 3-Star, 2-Star or 1-Star stamp to your album. Similar applies to the 4-Star and 5-Star Jokers. After receiving a Joker, it must be used to replace a missing stamp within 24 hours.