WowAce

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

The original source for where things are in Pandaria

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

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

Tracks rare drops, including companions and mounts

Find five Ephemeral Crystals, get a pink hippogryph

Dynamic mount macro generator

Collectinator is an addon which will scan your pets and mounts and provide information on how to obtain them.

mount and companion manager

MiniPet, Always keep your little companion with you, based on the work of Carra.

Displays Pet Info for Hunters and Warlocks. Also keeps track of Stables and Pet and Demon skills.

Auto and random summon highly customizable for your pets and mounts, with Data Broker support.

Add-on that shows which mounts can be farmed this week

The One-Key-Mount™ — Simple to use, configured with Rock

A Mount and Companion manager

Pet Theory

Shows the health of the player's current bodyguard.

Don't underestimate your little critters!

Interface-central mount management

Generate a macro with random mounts