Put the quiz on the screen the venue already has

Run the host view on the TV or projector the venue already has: the question, the countdown and the leaderboard, laid out to be read from the back of the room.

The host view is the display

There is no second app to run on the television. The screen you host from is the screen the room reads: put it on the TV over HDMI, mirror it, or run it on a laptop plugged into the projector, and that is the whole of the setup.

It means there is nothing to keep in sync, nothing extra to log into, and no second device to have gone to sleep at the wrong moment.

What is on it at each point in the night

The screen has three jobs across a question, and it does them one at a time rather than showing everything at once.

The question
Up first, large, with its options. It is on every player's phone as well, so the screen is a shared reference rather than the only copy, which is why it stays readable in a room where the back tables cannot see it perfectly.
The countdown
Running alongside, on the same clock as the phones. The room can see how long is left without looking down.
The leaderboard
After the question closes, with the new standings. This is the bit the room actually watches, and the reason to have a screen at all.

What you need

A screen, and a way to get a browser onto it. Most venues already have both: the television that shows the football, and a laptop. A cheap HDMI cable does the job; a smart TV with a browser does it without the laptop.

Sizing is worth a thought. The thing to check is not whether the question is legible from the bar but whether the leaderboard is, because that is what people look at from across the room.

If the venue has no screen

It still works, and this is not a consolation prize. The question is on every phone in the room already, so a taproom with concrete walls and no television runs a quiz perfectly well, the host reads the question out if they want to, and the standings are on the phones too.

What you lose is the shared moment when the leaderboard updates in front of everybody. That is a real loss, and it is the one good argument for finding a screen.