The Wall Quiz is a trivia game with a gambling layer borrowed from the TV format: you place bets on zones of a wall, answer questions, and balls drop through the wall to determine what your answer was actually worth.
So knowledge gets you part of the way and the ball drop does the rest, which is what makes the format tense rather than simply a quiz.
Balls drop through the wall into prize zones you've bet on, so your trivia answer sets up the bet and the physics decides the payout.
No — knowledge determines your betting position, but the ball drop introduces chance, which is what makes the format dramatic.
Yes — tap to bet and answer. Nothing to install.