From MothCraft

in the Settings menu in the Main Menu item you can access the friends menu OR by using the /friend command. This is a GUI friends list. on the top, you can add a friend. and in the settings you can turn on and off allowing friend requests being sent to a player or teleporting to a friend. these are off by default. This allows your friends to teleport directly to you and keep track of when you or they were last online.