WowAce

Officially the original source for where things are in the Broken Isles, in HandyNotes

The original HandyNotes source for where things are in Battle for Azeroth

The original source for where things are in Pandaria

Officially the original source of knowledge of where things are in Draenor during Warlords, in HandyNotes

Wowhead Data dump for GatherMate2

Achievements

Marks the locations of Hallow's End candy buckets on the worldmap and minimap.

Caith skin for Masque.

Serenity skins for Masque.

Find five Ephemeral Crystals, get a pink hippogryph

Apathy skin for Masque.

Marks the locations of Midsummer Fire Festival bonfires on the worldmap and minimap.

Entropy skins for Masque.

Where the lore is at

Cirque Skins for Masque

Onyx skins for Masque.

Teleporters in Suramar? Sure, why not?

LiteStep skins for Masque.

Show all the leyline taps in Suramar

Show all the orbs for triggering Kosumoth