If you're using the Check-in feature of Attendee Manager, either from the browser or using the iOS Check-in App, you can set up text or email notifications when certain guests Check-in on the day of the Event.
Check-in notifications are setup from the More dropdown in the full-screen view of Attendee Manager.
Notifications are associated with the Tags assigned to attendees. Enter in a phone number or email address and assign a Tag. Only the digits of the phone number should be entered. Do not enter any dashes or parentheses.
An SMS text message and/or email notification will be sent out to each recipient whenever any guest with the associated Tag is Checked in at the Event.