Push Notifications: Without enabling this you won't be able to receive notifications, which could mean you miss out on important event updates.
Storage: This permission allows you to choose photos from your phone's gallery to post to the Activity Feed, save any photos taken from the app, and open and save any PDFs downloaded from the app.
Locations: This permission allows you to receive notifications from beacons, which are location specific.
Calendar: This permission allows the app to export calendar items from your personal agenda to your device, making it easier to plan your day at the event.
Camera: Granting the app access to your camera allows you to use the QR Scanner and post photos directly to the event's Activity Feed.
Contacts: By allowing the app to access your contacts, you can export any new contacts you've made during the event to your device