A simple vanilla WoW addon that adds a small window that tells you how many more mobs (of the last type killed) you need to level up!
No hassle, no setup, no problem!
Accounts for rested XP remaining!
Takes the average of the last three mobs killed, so may not be 100% accurate. This approach was needed because otherwise the number would change after every mob kill and not provide a steady answer. Even level variations between the same mob would cause changes.
Made for Vanilla WoW 1.12.1.