Draw lots
In Parameters, set the number of lots (2 to 30) and how many of them are winners. Each person taps a face-down lot to reveal it: a star means a winner and a dash means a blank.
It works like drawing straws. The winners are placed at random before anyone chooses, so the order in which people pick does not change their chances. Tap the new round button to shuffle again.
Questions
Does it matter who picks first?
No. With K winners among N lots, every lot has the same K in N chance.
Can there be more than one winner?
Yes, any number from 1 up to one less than the number of lots.