The ace up Apple's sleeve is their full hardware and operating system control on iOS devices. Siri is just another example of this. Third-party software on iP

The ace up Apple's sleeve is their full hardware and operating system control on iOS devices. Siri is just another example of this. Third-party software on iPhone is sandboxed in many ways that give Apple apps a competitive advantage. With regard to Siri and voice control, no third party app is allowed to respond to the critical press-and-hold-home-button shortcut. Another example is the hardware volume buttons, which Apple repurposes for Camera.app shutter control, but access to which was denied for the popular third party Camera+ app for that same purpose. Only Apple's Camera.app gets a lock-screen shortcut. Only Apple apps are allowed to access the carrier's SMS and voicemail. Only iBooks got access to real brightness control (may have changed in iOS 5). Only Apple apps can show a photo preview (e.g. MMS/iMessage) in a notification. Only Apple apps get to put widgets in the iOS 5 Notifications panel. The list goes on...