One of Apple's iOS apps that is getting updated in iOS 6 is Find My Friends (Free, App Store link) which could be helpful for parents1 wanting to keep track of their kids comings and goings from school/etc.
As Fraser Speirs points out: 2
Find my Friends as detailed on Apple.com:
Find My Friends is a great way to share locations with friends and family. Those who share their locations with you appear on a map so you can quickly see where they are and what they’re up to. And with iOS 6, you can get location-based alerts — like when your kids leave school or arrive home. Find My Friends can also notify others about your location, so you can stay connected or keep track of the ones you love.
What this means is that you can set up a geo-fence - for example tell Find my Friends the address of your kid's school - and then whenever your kid enters or leaves that geo-fenced area, you get a notification.
3 or 4 years ago, I might have trusted Google with doing this. Now I wouldn't. Right now I do trust that Apple won't abuse or mistreat this level of information about me - we'll have to see where Apple is in 3 or 4 years to know if that trust has been broken or not.