The Drop Tracker is part of the Analytics functionality which will be introduced in the Summer Update 2017. If you activate the Drop Tracker and a creature drops one of your tracked items, you will be notified about it in the Drop Tracker window, Game Window and Loot Channel or Server Log Channel (if Loot channel is closed). It also shows how many times you have looted an item since you started to track it. Premium players can track up to 50 items, while free account players can track up to 5 items.
Note: This feature was initially called Loot Tracker but was renamed during the Test Server to better reflect its use.