The iPhone Application Development There are 5 steps necessary to develop an iPhone application Concept Is an iPhone application your best medium What will your application do Categories Do you have a unique idea? Review the list of current applications to see what is out there and see how yours will be different. "Before investing in an iPhone app, step back and ask the tough business questions about why you are developing it, who your audience is, and if it is the best medium to reach your target Buy versus Build Buy Build Build From Scratch Third Party Application Builders Pay: AppMakr Swebapps My App Builder iSites TapLynx AppBreeder GameSalad AppIncubator Free: Resource Requirements Software iPhone SDK For step by step coding directions reference http://developer.apple.com/iphone/library/referencelibrary/gettingstarted/Creating_an_iPhone_App/index.html An iPhone application iPhone OS The iPhone and iPod Touch SDK uses Objective C, based on the C programming language. Currently, is only available on Mac OS X 10.5 and is the only way to write an iPhone application. All applications must be cleared by Apple before being hosted on the AppStore, the sole distribution channel for iPhone and iPod touch applications. However, non-Apple approved applications can be released to jailbroken iPhones via Cydia or Installer. The iPhone OS is being renamed to iOS with the release of version 4. iPhone OS Make the application available To make your application avaiable you have to publish it on the App Store.