How To Build An IPhone App

Developing for the iOS App Store is a no-brainer. If I said that a measly investment of £250 was enough to open up a market of 150 million consumers, the ears of any smart developer should prick up. The sheer size of the App Store is staggering, with more than twice as many apps available as all the competing stores combined. All you need to join in is an idea, a Mac (for coding), and this tutorial. To make software for iOS devices - that's iPads, iPhones and iPod Touches - you need just one software package: the iOS SDK from Apple. I should stress that this can only be done your Mac, because the iOS SDK isn't available for any other platform. In fact, you're pretty much limited to using Apple's hardware, software and development tools. This is why many people refer to iOS development as being as a 'walled garden' - Apple is very protective about who makes apps and what goes into the store.

The Mac requirement is a hurdle you can't really vault over, but I will say this: even if you're dedicated to Windows or Linux, a Mac is an excellent purchase. We rarely see more solid or reliable PCs. If you later decide you've built an app you want to sell, you should pick up an iPod Touch for testing purposes (£180), then sign up for a commercial iOS account (£60). If your 59p app sells just 500 copies - if just 0.00033 per cent of iOS owners buy it - you've made your money back and everything else is profit. Once you've created your account, you need to download the latest SDK. At the time of writing, that's Xcode 3.2.5 with iOS SDK 4.2. This package includes everything you need to make iPhone and iPad apps. The installer is very simple: just click 'Next' until the copying process starts, then give it about 30 minutes to perform its magic and you're ready to get going. We're going to make a simple to-do list manager, building on some of the basic user interface elements that are common to iOS apps.