Facebook Messenger's new "Live Location enables" users to share where they are with a specific user or group of friends for 60 minutes. Once activated, you'll be able to be found on a map by those friends, and Facebook will show how long it would take to reach the friend who shared their location by car if you're trying to plan a meetup. Naturally, you can stop sharing your location at any time, and a little clock shows how much longer your location will be available for.
Messenger also still lets users share a specific static location without giving continuous updates -- that's good if you're trying to meet somewhere specific but don't need your contacts to be tracking your every move. By default, the app now asks you for the "live location" sharing feature, so just make sure you tap the red pin and drop it on your map if you don't want to activate the tracking option. The features are found in the latest version of Facebook Messenger for Android and iOS -- the updates are out now if you want to give it a shot.