Try on different gear and see their total stats and their differences. In short, an ingame CT-Profiles-like addon.
Pawn - World of Warcraft Addons - CurseForge
Overview - KiwiPlates - Addons - Projects - WowAce
api - Pages - Ace3 - Addons - Projects - WowAce
World of Warcraft Addons - CurseForge
Download WoWEquip - World of Warcraft Addons - CurseForge
BenikUI - The ElvUI Edit - World of Warcraft Addons - CurseForge
WoWEquip : Miscellaneous : World of Warcraft AddOns
Pawn - World of Warcraft Addons - CurseForge
WoW Interface Design for Beginners - Wowhead
ElvUI Addon Guide - How to Install and Customize - Wowhead News
World of Warcraft Addons - CurseForge