Advance Starter is an easy-to-use and very quick adapted tool that can edit your starter Pokemon.
Type: Pokemon Editing
Compatible with: Pokemon Ruby, Sapphire, Emerald, FireRed, LeafGreen
Supported OS: Windows
Advance Text will help you get out of that case because it is the current most-used text editing program for any GBA Pokemon game.
Advance Trainer is a tool that you can edit every wild trainers you meet in your favorite Pokemon game.
When choosing a tool to edit all the palettes in a Gen III Pokemon game, do not forget Advanced Palette Editor.
A-Tack is a tool for editing the attack indexes of GBA Pokemon games. All the moves can be found here.