I've used
Outfitter for as long as I can remember, and is very handy for druids and everyone else that changes forms, stances, stealth and so on. I'll just paste the info from the download site:
Quote:
Outfitter allows you to create multiple outfits and equip them with a click of your mouse. You can layer outfits, create outfits optimized for a particular attribute (ie, fire resist or maximum defense), and have outfits which automatically equip.
Automatic outfits include riding, Argent Dawn (plagulands), battlegrounds, and class-specific automatic outfits like shadowform, stealth, warrior stances and druid shapeshifting.
Very handy for example when you carry different sets of gear, like a healing set/dps set, and for feral druids where you automatically equip dps gear in cat form and tanking gear in bear form etc.