Ever wanted to know what experience your friend is at? With is addon you can, as long as you both have it installed you can see their exp through a little bar on their party frame and the amount on a tooltip. Both persons must have the addon installed and you must be in group. Check Interface Options for settings as well.
Features:
1.) Shows a party members EXP (as long as they have the addon too)
2.) Give a "Level Up" callout to party and/or guild (configurable)