It's called "Restrictions". It's already part of iOS. The problem is that it doesn't ask you for your password when an app wants to use the location services but rather avoids changing any settings, so new apps cannot use the location services.
I have Restrictions enabled so that Find My iPhone cannot be disabled. The thief can always turn the iPhone off or remove the SIM card, but iPhone thieves are usually the kind of people you'd want to shoot for being so stupid, so they might not do that. In fact, NOT having a passcode lock may help because the thief would not consider wiping the phone to gain access if access is already granted.
Think about it; if you steal an iPhone that you can't get into, you're going to Google "how to break passcode on iPhone" and restore it. If you steal an iPhone that you can use that is secretly being tracked, you might just leave it as it is.