ACP
Allows players to turn on/off mods and reload their ui in game instead of needing to log out. Also lets players make sets of mods.
Curse, WoWInterface
WoW Insider Review
Addon Loader , ,
AddonLoader is an addon that loads other addons automatically, as and when they are needed, which speeds up the logon process.
Note that addons need to be aware of AddonLoader for this to work; if you see "X-LoadOn-..." tags in their .toc files, they are!
Curse
AddonSwitcher
Small and simple tool to enable and disable your addons quickly. Make custom profiles like "raid", "grind" and "pvp".
WoWInterface
Ampere
A small addon designed to mirror the functionality of the login screen "Addons" button in-game. It's designed to fit inside the config GUI introduced in patch 2.4. Amp lets you quickly enable and disable addons, reload the UI, and load LoadOnDemand addons.
WoWInterface, Curse, github
LoadIT
LoadIT was designed to allow in-game management of your addons. Using LoadIT, you can enable, disable, and load addons during gameplay. You can create profiles of addons, and switch between these profiles on-the-fly. I designed LoadIT, because I have sets of addons that I use for instances like Molten Core, Blackwing Lair, and Onyxia's Lair, but I don't care to have many of them loaded while I'm in battlegrounds, due to the amount of lag some addons create during PVP.
Curse
TooManyAddons ,
This mod is like an 'outfitter' of mods. Type a title and click new profile, select what addons you want to load with this profile, and whenever you click load profile the checked profile will load those, and only those, addons.
Curse
