My Bonus Card keeps disappearing!
The "bonus cards" that appear on the top right corner of the screen in certain games work like this:
When the "bonus" card comes into play, you are shown two cards at the top right corner of the screen with the one on the furthest left side being the "target" card. This card will disappear and the card on the right side will remain and keep displaying different symbols. You'll need to tap on it when it displays the one that matched the target card shown beforehand.
So let's say you start a game of Turtle Traffic and there is a bonus card on the left of the top right corner of the screen, displaying a star. It will disappear after a few seconds and the card on the right side will start displaying different symbols one after the next. You just need to tap on this card whenever it displays a star, as it is the "target symbol" that was displayed at the start. If another target card appears later on and displays a fish before disappearing, then your new target will be a fish.