Just as the iPhone and iPad can extend the reach of the user, the device possibilities and the development environment can extend your reach as a developer. To make sure that you’re reaching in the right direction, it helps to understand Apple’s perspective on what iOS apps should be.

The company clearly has done some serious thinking about it, for far longer than anybody else out there, having taken years to bring iOS devices to market under a veil of secrecy.

So what does Apple think? Spokespeople often talk about three different application styles:

  • Productivity applications use and manipulate information. The RoadTrip app is an example, and so are Bento and FileMaker Go (FileMaker), and Apple’s iWork apps — Keynote, Pages, and Numbers. Common to all these apps is the use and manipulation of multiple types of information. (Not the Productivity category in the App Store — that’s a marketing designation.)

  • Utility applications perform simple, highly defined tasks. Google’s YouTube app is an example — it deals only with the YouTube videos. The Brushes app for painting (by Steve Sprang) is considered a utility, as it performs a simple, highly defined task. (Again, not the Utilities category in the App Store, although many of those apps are considered utility apps because they perform simple, highly defined tasks.)

  • Immersive applications are focused on delivering — and having the user interact with — content in a visually rich environment. A game is a typical example of an immersive application.

Although these categories help you understand how Apple thinks about iOS apps (at least publicly), don’t let them get in the way of your creativity. You’ve probably heard ad nauseam about stepping outside the box. But hold on to your lunch; the iOS “box” isn’t even a box yet. So here’s a more extreme metaphor: Try diving into the abyss and coming up with something really new.