True Iron Ore

Alchemy

 * Draenic Philosopher's Stone

Blacksmithing

 * Secrets of Draenor Blacksmithing
 * Smoldering Breastplate
 * Smoldering Greaves
 * Steelforged Aegis
 * Steelforged Axe
 * Steelforged Dagger
 * Steelforged Greataxe
 * Steelforged Hammer
 * Steelforged Saber
 * Steelforged Shield
 * Truesteel Grinder
 * Truesteel Helm
 * Truesteel Ingot
 * Truesteel Pauldrons
 * Truesteel Reshaper

Engineering

 * Didi's Delicate Assembly
 * Gearspring Parts
 * Goblin Glider Kit
 * Secrets of Draenor Engineering
 * Shieldtronic Shield
 * Stealthman 54

Jewelcrafting

 * Glowing Blackrock Band
 * Glowing Iron Band
 * Glowing Iron Choker
 * Glowing Taladite Pendant
 * Glowing Taladite Ring
 * Mastery Taladite
 * Shifting Blackrock Band
 * Shifting Iron Band
 * Shifting Iron Choker
 * Shifting Taladite Pendant
 * Shifting Taladite Ring
 * Stamina Taladite
 * Taladite Crystal
 * Taladite Recrystalizer
 * Whispering Taladite Pendant
 * Whispering Taladite Ring

Leatherworking

 * Supple Helm
 * Supple Shoulderguards
 * Wayfaring Helm
 * Wayfaring Shoulderguards

Tailoring

 * Hexweave Cowl
 * Hexweave Mantle

Currency for

 * Primal Spirit
 * Recipe: Powerful Truesteel Essence
 * Recipe: Primal Gemcutting
 * Recipe: Riddle of Truesteel
 * Schematic: Precision Scope Tuning Kit

Objective of

 * A Bit of Ore
 * Out of Stock: True Iron Ore

Speculation
It is believed that Outland's Fel Iron is a corrupted variant of True Iron.