Edit: since the time this post was made, Blizzard has shut down some iPod apps. I don’t think that Warcraft Chest or Warcraft Characters are available at this time.
For my birthday I was the happy recipient of the iPod Touch. This handy little gadget has a million uses, from the calendar to watching movies to productivity tools with a web browser to music. The first thing a new Touch owner does is download a bunch of new apps from the App Store.
After getting the necessities, I browsed around the App Store for something useful. I found a few Warcraft apps that have really helped out. And they are all free. Edit: since I wrote this post back in December, these apps have been changed so that they are no longer free.
Do you like using AtlasLoot in game? There is a similar program for the Touch and iPhone called Warcraft Chest.

It has almost everything AtlasLoot does. You can search through loot lists for raids and instances, on normal or heroic, and it will show you the full item description just like it appears on WoWhead. It doesn’t require internet access. I use this when sitting around during down time, or when I just want to look at the new stuff in Wrath.
A second app that has become useful is WoWTalent. It is a fully functional talent calculator for your iPhone, iPod Touch. It has all of the trees and talent descriptions, and allows you to build a complete spec and then save it.

This would be really useful for someone who respecs a lot. I use it when I go from my Combat leveling spec to my Mutilate instancing spec or back. I can pull up a spec on my iPod and refer to it as I put points into my trees. No more mistakes!
The third app I got is called Warcraft Characters. It is a very easy to use armory app. It retrieves your characters from the armory and shows you abilities, talent spec, skills, etc… It does require internet access to refresh it, but you can view the cached information with no access.

All of these do the same functions as in-game add-ons. But I am trying to cut down on my add-ons, and I hate alt-tabbing out of the game to look stuff up. So these apps for my iPod Touch are very useful and easily accessible while I am playing or just sitting in traffic. They are all available for free through iTUnes or the App Store on your iPhone or iPod Touch.