Lets you skip gossip or auto complete quests, you can add quests to be skipped by holding the ALT key down and clicking the quest you want, for example to add the Scryer Sunfury Signet quests, go to the turn in NPC hold ALT and click "Single Sunfury Signet" and "More Sunfury Signet". You'll need to go to the turn in page first for both of them (The one that lists items required) before it'll start auto completing.
Currently, it'll auto complete all Alterac Valley quests but more pre-defined lists will be added eventually.
It'll automagically figure out which quest to auto complete even if you manually add it through ALT + click and the NPC has multiple quests that requires the same item by auto completing the quest that requires the most of the item.
For example, if you have 23 Sunfury Signets, it'll auto complete More Sunfury Signet (10 signets) twice, then complete Single Sunfury Signet (1 signet) three times instead of doing More Sunfury Signet twice and stopping, or making you do Single Sunfury Signet 23 times.
You can disable the auto skipping by holding down SHIFT, and you can remove quests that are set to auto skip by ALT + clicking again. No slash command currently.

