The iPhone SDK is a proprietary Software Development Kit from Apple Computer, Inc. that is required to create native applications, games and media for the iPhone, iPod Touch and now, iPad devices.
What are web developers doing with this SDK? We're glad you asked. As the devices are proprietary to Apple, many mobile-friendly platforms, like Java and Flash don't work on them. While we specialize in mobile web app development using HTML5 and jQuery optimized for Safari Mobile's WebKit based browser, having a handle on the core underpinnings of these awesome Apple devices is key to our mobile development process. We've worked hard and are fully up to speed with the SDKs Xcode environment, Objective-C language and Cocoa Touch layer.
Plus, we wanna help you develop really cool apps that leverage the mulit-touch interface and tilt, triple-axis accelerometer capability for the iTunes AppStore.