The raffle is a great way to get attendees to open the app and keep them engaged. When you run it, a random attendee will be selected. They will see "You are a Winner!" on their screen. Their name will also show up on the presenter's screen, but that won't tell you much if your attendees are anonymous.
Who is eligible for the raffle?
There are a few options for the raffle to tailor it to your use-case.
Require Opt-In asks the attendees to tap on their screens to confirm they want to be in the raffle. You can use this to select a random volunteer from the audience.
Require Email asks attendees for their email address. If you offer a prize, this is a great way to get a list of emails from your attendees.
Unconstrained picks from all attendees. It's very simple from the attendee's perspective, so it's a good way to get attendees to open the app.