Geofencing: The Bug
My problem with geofencing seemed to be a bug in the arrival mechanism. Setting up a reminder to trigger when you cross a geofence requires Location Services to run from the moment that the reminder is set until you satisfy the conditions of the Reminder. That's how geofencing works. But in my case, the trigger didn't fire when I arrived at the location--it fired when I left it. But in order to know that you've left, iPhone must know that you've arrived, which the bug is currently preventing. It's a Catch-22, not to mention a battery drainer.