If you're going to venture out into the wilds of Nintendo's Pokémon series, hoping to catch, imprison and then enslave some adorable little creatures, then you should probably bring the iPokédex with you.
It's a handy little guide for the game which includes (almost) every single Pokémon from every Pokémon game, as well as their complete move sets, abilities and even family trees and individual statistics.
What it is, then, is a reference guide for sorting out which Pokémon you're going to use in a particular fight, and how best to employ their attacks. It is not a strategy guide for any of the actual games.
The app's presentation is great, prioritising function over form, and you're only ever a click or two away from all the information you need.
About the only downside with it at the moment is the fact it's lacking Pokémon and their moves/abilities from the new Pokémon Black & White games, but the app's developer promises that stuff is on its way soon.
Everything else, though, is great, especially considering the app is free.