Checking into an Event and/or editing attendance for an Event?

Still learning this new plugin and have a couple of questions. My site will reward users for the events they create, manage and how many members attend those events. Is there any means by which a user can "Check In" to the event - either at the event via mobile or as they leave for the event on their home computer, etc?

Is there any way for the event administrator to edit the attendance after the fact?