Hoenn walkthrough section
Pokemon Ruby and Sapphire Phase 2: Devon Corporation
Knuckle Badge Return the Devon Goods to the researcher, then go to the Devon Corporation. The president gives you two errands: deliver the Letter to Steven in Dewford and deliver the Devon Goods to Captain Stern in Slateport.
Phase 2 Knuckle Badge Devon Goods, Dewford Town, Granite Cave, Steven's letter, and Brawly. 02 / 10 
Phase 2 section 4 of 9
Return the Devon Goods to the researcher, then go to the Devon Corporation. The president gives you two errands: deliver the Letter to Steven in Dewford and deliver the Devon Goods to Captain Stern in Slateport.
Devon Corporation
Return the Devon Goods to the researcher, then go to the Devon Corporation. The president gives you two errands: deliver the Letter to Steven in Dewford and deliver the Devon Goods to Captain Stern in Slateport. He also gives you the PokeNav.
The PokeNav is not a battle tool, but it is part of the Gen 3 identity: map, Pokemon Contest condition, Trainer’s Eyes rematch information, and ribbon tracking all live there. Match Call is the Emerald replacement for Trainer’s Eyes, so Ruby/Sapphire players should look for Trainer’s Eyes instead. Once this cutscene is done, go back through Petalburg Woods to Mr. Briney’s cottage on Route 104.