Ok
Do you remember getting a square of paper, folding it into 8ths(?) Folding it back into itself to make a device you can hold and flick it back and forth.
You'd ask your friend to choose a number from the top, then you'd flip the thing that amount of times, and you end up getting an instruction or something at the end.
I'm "teaching" (it's just an after school club as a volunteer don't worry nothing official) some children how to make these in the club, but can't find anything online to help out with ideas as I've no idea of the search term !!