Fresh off of a solid launch, the folks over at Disney have released an iPad app for Disney Infinity. The app itself is Toy Box oriented, as it allows you to build and create worlds that can be put into the console version. You'll start off with a limited amount of items (and just Mr. Incredible), but the real way to use this app is to sync it with your console game, which will allow you to unlock all of the pieces you've encountered in your save file.
You can also use the code that came with each physical toy to unlock them on the app. The app is free until October 15th, at which point it'll revert to a mystery price-point.
Disney Infinity [iTunes]