When you jailbreak an iOS device for the first time, you have a lot to learn. That's just the first of many ways jailbreaking is unlike the out-of-the-box Apple experience. To get a better sense of the purpose and potential of jailbreaking, I talked to one of the best.

chpwn is the creator of jailbrea.kr, a single destination to keep you posted on the latest jailbreaks for all devices and OS versions. He's also created a host of apps and services that really make the most of the freedom afforded by jailbreaking. He doesn't just break the conventions of iOS for the sheer joy of it; he understands what the system needs but doesn't have.

ReadWriteWeb: Why jailbreak? What does an iOS user gain by jailbreaking?

chpwn: Jailbreaking is about getting around the restrictions that Apple puts in place, so you might think that jailbreaking is mostly about getting the kind of apps that Apple doesn't allow.

But jailbreaking is really about a lot more than that. Most of what's available in Cydia (the jailbreak "equivalent" to Apple's App Store) are extensions, tweaks, or modifications to what's built in to the iPhone or the iPad. If you've ever used Firefox's extension system, that's the about the closest equivalent to what's available in Cydia.

Some tweaks improve something that's already there: my Infinifolders let you add more icons to folders than Apple's standard 12-icon limit. Others make it easier to use: @phoenixdev's Music Controls Pro adds gestures and other controls to dozens of music apps. Some of the most cool are the extensions that provide completely new features: I personally like Ryan Petrich's DisplayRecorder, which allows you to record and share videos of whatever is running on your screen.

None of these are traditional "applications," like what's in the App Store, though. Many don't even have icons on your home screen. They just hook into various parts of the OS, and modify what's needed to add the feature.

Don't miss tomorrow's installment of Jon's adventures in jailbreaking, in which he reports back from his own month-long experiment.
RWW: What are some typical use cases for which your average user would benefit from jailbreaking?

chpwn: A lot of people jailbreak for very simple reasons. Before it was added in iOS 4, just the ability to add a wallpaper to your home screen was often what led many people to jailbreaking. Nowadays, one of the most popular reasons is to add quick settings and toggles for commonly used functions: the extension SBSettings lets you turn on and off Wi-Fi and other connections right from Notification Center.

Theming, too, is popular. Cydia has tens of thousands of themes available, which can make iOS look like anything from Windows 7 to a movie poster - or just improve or customize the existing look. Customization, in general, is one of the big themes of jailbreaking. Most iPhones look identical, so lots of people want to be able to make theirs stand out.

RWW: What are some of the most interesting modifications you've made or come across?

chpwn: One of the most visually impressive tweaks I've seen is Barrel, by Aaron Ash. It takes your home screen icons, and then adds 3D transitions as you swipe from page to page. They might turn like on a cube, or spin like a wheel, but then smoothly end up back where they started. It's hard to describe; you have to see it in person for the real effect.

Another one of my favorites is Conrad Kramer's Graviboard, which adds gravity to your icons. Rather than just a boring grid, you can pick up your icons and throw them around your home screen, bouncing with simulated physics and gravity in whatever direction you turn your device. It's a lot of fun, and definitely a cool way to show off jailbreaking.

On the more practical side, Jay Freeman (@saurik, the creator of Cydia) makes Cyntact, which just adds pictures next to each of your contacts names, throughout your phone. It seems simple, but it helps a lot in practice to quickly find the right contact. The popular time-based screen-dimming tool f.lux is also in Cydia, and helps quite a bit with reading at night.

None of these even conceptually make sense in the App Store. They modify the entire phone, not just a self-contained icon. So it's definitely interesting to see how iOS might be improved if it was open to more outside modification.

TOMORROW on ReadWriteWeb: Jon reports back from his own month-long adventure in iOS jailbreaking.

Disclosure: Grant "chpwn" Paul is related to ReadWriteWeb Channels Editor Fred Paul.