QR code joining, with no app
Players scan the code on their table and they are in the quiz.
Each table has its own permanent QR code. A player points their phone camera at it, types a name, and is in. There is nothing to download, no account to create, no email to confirm and no password to forget. That matters more than it sounds: every install and every sign-up between the poster on the table and the first question is a team that decides not to bother.