This addon show in a simply way the current xp of each group members with color of class. Each group or raid members must have the addon.
Because of restriction of the API of blizzard, the addon can't add bar while in fight, so it detect others players and save datas but not show these data while in fight. At the end of the fight, the addon expand the list of player automatically. Otherwise, if the bars of players are shown, the update work while in fight.
Let me know if you want some improvment.