Point, scan, done
Sign in on the night and the scanner opens in your browser — no app store, no downloads. Point the camera at a ticket and you get an answer in under a second: valid, already used, or not on the list.
ValidGreen check, guest counted in, list updates for every scanner.
UsedRed flag with the time and door it was first scanned at.
UnknownNot on this event's list — check the name against sales manually.