This helpful addon is perfect for leveling because it shows you where all your quest locations are and shows you what/who you need to kill/take/talk with. It's also perfect because it tracks your information on your quests, and most importantly stacks with the Cartographer addon.
This is also a helpful addon because it reveals the map of all regions in Azeroth and Outland. All the regions will be explored like you've been there. It stacks with the Quest Helper too.
Thanks on feedback, and if you also have some helpful addons for 2.4.3, feel free to post them here.