When you create your card, you can flip over a square to enter a clue/question. Whatever you enter on the back of your square will appear in the call list for your bingo game. For example, to help kids learn animal words, you might put the word "Bear" on the front of the square, and a picture of the bear on the back. When you play the game, the image of the bear will appear in the call list for your students to see. If they recognize the literal word "Bear" on their card, they would mark it.
You can use question/answer-style bingo to quiz players about anything!