Application support

The central processing unit (CPU) used in the iPhone and iPod Touch is an ARM-based processor instead of the x86 (and previous PowerPC or MC680x0) processors used in Apple's Macintosh computers, and it uses OpenGL ES 1.1[8] rendering by the PowerVR 3D graphics hardware accelerator co-processor.[9] Mac OS X applications cannot be copied to and run on an iPhone OS device. The applications must be written and compiled specifically for the iPhone OS and the ARM architecture. The Safari web browser supports Web applications as with other web browsers. Authorized third-party native applications are available for devices running iPhone OS 2.0 and later through Apple's App Store.
[edit] Included applications
In version 3.0, the iPhone home screen contains these default applications: Messages (Text messaging, MMS), Calendar, Photos (with video viewer on 3GS), Camera (Video recording and auto-focus enabled in iPhone 3GS), YouTube, Stocks (Yahoo! Finance), Maps (Google Maps, with Assisted GPS on iPhone 3G and 3GS), Weather (Yahoo! Weather), Clock (with stopwatch, alarm clock and timer), Calculator (with scientific version), Voice Memos, Notes, Settings, iTunes (with access to the iTunes Music Store and iTunes Podcast Directory), App Store, Compass (iPhone 3GS), Contacts (with landscape support), and the Nike + iPod app (iPhone 3GS and iPod Touch 2nd generation) that interfaces with the optional Nike + iPod sensor. Four other applications delineate the iPhone's main purposes: Phone, Mail, Safari, and iPod.[10][11]
The iPod Touch retains many of the same applications that are present by default on the iPhone, with the exception of the Phone, Messages, Compass and Camera apps. The "iPod" App present on the iPhone is split into two apps on the iPod Touch: Music, and Videos. The bottom row of applications is also used to delineate the iPod Touch's main purposes: Music, Videos, Safari, and App Store (Dock Layout was changed in 3.1 Update).
[edit] Web applications
At the 2007 Apple Worldwide Developers Conference Apple announced that the iPhone and iPod Touch would support Web applications created by third-party developers using technologies such as Ajax through the Safari web browser.[12] Apple Inc. considers that web applications capable of providing a sufficient user experience obviate any need for jailbreaking. Additionally, they determined that making native applications other than their own were unnecessary. However, the aforementioned web applications were unsuccessful,[citation needed] because the JavaScript engine running in Mobile Safari was not powerful enough to run applications satisfactorily.[citation needed]
[edit] Unsupported third-party native applications
The iPhone and iPod Touch can only officially install full programs through the App Store.[13] However, from version 1.0 unauthorized third-party native applications are available.[14] Such applications face the possibility of being broken by any iPhone OS update, though Apple has stated it will not design software updates specifically to break native applications (other than applications that perform SIM unlocking).[15] The main distribution methods for these applications are the Cydia, Icy, Rock, and Installer utilities, which can be installed on the iPhone after jailbreaking.

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