Does the new overnear Facebook app for iOS show friends’ location only if nearby or at any place?
it depends upon the user if he or she updated its location
Only when they are "near" you. But it will show it only if they have their facebook showing their location, if not you won't see where they are.
Is it facebook's app or a third-party app?
It's a third party :)
It was not only answered correctly but even sub-question was acknowledged