From GameBrew - a wiki dedicated to Video Game Homebrew.
PokebattleDS is a DS homebrew game inspired by the commercial game Pokemon.
Fight with your Pokemon, choose the command for your Pokemon and the goal is to defeat your opponent.
D-Pad - Scroll
A - Confirm (menus)
B - Go back (menus)
X - Activate random shouts of your pokemon
Start - Start (main menu)
L+R+Start+Select - Exit battle to main menu
Tested on iTouch2 (firmware 3.3e).