Apple has updated its and Find My Friends with iOS 6 support and a few new features, including push notifications for locations.
Arstechnica digs deeper into the new features of the app, which includes a revamped interface and the ability to send texts to friends from within the app. They also note one particularly notable new feature: push notifications for friend locations:
But the most significant new feature—and the one that will undoubtedly cause at least a bit of controversy—is the ability to set notifications for when your iOS-using friends arrive or leave a certain location. You can set this notification by viewing a specific friend's location and then tapping the "Notify Me" button on the top right. This brings you to a screen that allows you to decide whether you want to be notified when that person is coming or going, and with which address to associate the notification.
Arstechnica notes that you can disable permissions from friends but it disables the Find My Friends functionality completely for that individual, not just automated notifications.
Find My Friends is a free download on the App Store [Direct Link].