FriendsETA lets you see how many minutes away your Facebook friends are without sharing your locations.
Any time you open the app, you can immediately see how many minutes away your friends are from you. This is great if you are waiting for someone to arrive, you can see how far away they are, or, if you are going to someone else, they can see when you will arrive.
A note on battery –
FriendsETA tries to be smart with the use of your GPS, however, as with all apps of this type, please note that continued use of GPS running in the background can dramatically decrease battery life.