Building on the iPhone SDK, Apple came up with a smart solution for distributing and installing iPhone apps. Modeling the success of its iTunes Store, Apple created the App Store -- a one-stop shopping location for all iPhone applications.

The App Store was revolutionary in several ways: It eliminated the need for advertising budgets, merchandising to physical stores and server hosting for application downloads, as well as the need to process customer transactions. Developers developed, Apple did the rest -- and took a sizable cut of profits for its efforts. The result was a level playing field for all developers, from large companies to small one-person operations and even presidential campaigns. (Remember the )

With all applications available in a single store, accessible from a computer or from an iPhone or an iPod Touch, users could easily track down applications in no time. Application installation via the App Store became the model of simplicity: Find an app, click "buy" and then wait a few seconds or minutes (depending on connection speeds) while the iPhone downloaded and installed the app without further ado.

The iPhone SDK and App Store weren't without faults. Developers could download the SDK for free, but they could only build applications installable on an iPhone after , paying $99 a year and signing restrictive nondisclosure agreements that stopped developers from even discussing their coding experiences with one another.

That was understandable before the iPhone 3G launch, but developers were annoyed that it took Apple months after the release and allow open discussion about iPhone development.