WowAce

Scan for rare mobs so you can find them and their loot

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

Tracks Raid/Instance/World Boss lockouts for all your characters, daily/weekly quests, currencies, trade cooldowns, and more!

Tracks rare drops, including companions and mounts

Displays the locations of Lunar Festival elders.

Show the transmog appearance of an item when you mouse over it, and shows collection-status in bags, shops, and elsewhere. Works on transmog, mounts, pets, and decor.

Uses various methods to scan your surroundings for rare or specified NPCs.

Achievements

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

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

Adds mob patrol paths to your map.

Teleporters in Suramar? Sure, why not?

Displays the locations of the chests for the Treasure, Treasure Everywhere achievement

QuestLog

Find five Ephemeral Crystals, get a pink hippogryph

Show all the orbs for triggering Kosumoth

Show all the leyline taps in Suramar

Books in Azsuna? Sure, why not?

Show where the chests are for Withered Army Training