Quest Announce is a great addon that keeps my group updated as to what quest we are completing through all the stages.
"Quest Completist"! To find if completed specific quest.I can't say how many times I have had to help back track quests for others and myself when a quest chain drops. This has been an invaluable tool! Why it hasn't been incorporated in the game yet, is beyond me.
"Fishing Buddy", so I can click on the water while mounted to fish instead of an icon. Plus to keep track where and what i have fished in the past.