Are you using alf.io for selling tickets and/or collecting attendes for your event?
Then this app is for you! Download it and follow the instructions on the website (https://alf.io/tutorials/check-in/) in order to get ready to welcome your attendees!
You can also allow sponsors to collect attendees data just by scanning the QR-Code on their badges, and therefore respecting attendees privacy.
An active Alf.io server and a reliable internet connection are required in order to validate the tickets.