iOS 5

Apple announced version 5.0 of its mobile operating system in June 2011, several months before it unveiled the new phone iOS5 would launch alongside. The operating system software went through several months of beta use before becoming available for iPhones, iPads and iPod touches. The iOS 5 updater is one of the biggest updates to the iPhone experience Apple has ever made. The standout new feature is Siri, the personal assistant built into iOS 5. Siri is only available on the iPhone 4S; the iOS 5 operating system itself can be downloaded onto the iPhone 4 and iPhone 3GS, but Siri doesn't run on those phones.

Siri uses natural language processing to interpret spoken commands. When you talk to Siri, your voice is uploaded to a server, processed, and sent back to the phone where action is taken. This only takes a couple seconds, and Siri can perform tasks like sending text messages, setting alarms, appointments and reminders, searching for restaurants, or making voice calls. By filling out contact information, Siri can understand commands like "Call my wife" or "Remind me to take my keys when I leave the office."

iPhone 4 and 3GS users still have new features to look forward to as well. Apple revamped its notification system to be more like the convenient sliding tray found on Android. Notifications no longer pop up in the middle of the screen, interrupting an app -- they're accessible in a tray that slides down from the top of the screen with a quick swipe. Additional new features:

• Apple's iMessage service integrates various communication sources like text messages and iChat. If you're sending a SMS to another iPhone owner, iOS5 defaults to iMessage, saving you a text.
• New iPhones can be activated without connecting to a computer, and data can be synced from iTunes over WiFi.
• The iCloud service syncs up to 5GB of apps, photos, and documents across multiple Apple devices for free.
• Twitter is built into the OS.
• The camera can be accessed from the lock screen.
• Light photo editing like red eye removal and cropping can be done from the Photos app.
• Apple's AirPlay video streaming works wirelessly. Video can be wirelessly mirrored from an iPad 2 or iPhone 4S to an Apple TV.
• Apple added new multi-touch gestures for multitasking.