Facebook integration was added to the operating system, allowing status messages, like buttons, and contact and event synchronization with several of Apple's apps.

Siri was expanded to more devices and updated with more functionality, such as the ability to make restaurant reservations, launch apps, retrieve movie reviews and sports statistics, and read items from the Notification Center.

iOS 6 also added LTE support for more carriers, the ability to purchase movie tickets through Fandango with Siri (USA only), a new button to reset the Advertising Identifier, and improvements to Maps in Japan.

The Phone app also received some enhancements, such as the option to reply with a message or set a callback reminder when declining a call, and the ability to enable a Do Not Disturb mode.

Critics noted that the operating system did not offer any significant speed improvements or major redesigns, but instead focused on refinements, with a general consensus that Apple "isn't overhauling things for the sake of it."

iOS 6 did not "completely change the way you use your device," but "each of the tweaks will make many daily smartphone actions easier across the board," and critics praised the refinement of "something that already works extremely well" as "something other companies would do well to emulate."

[3][4] Apple's Siri intelligent personal assistant, introduced in iOS 5 with the release of the iPhone 4s, was updated to include the ability to make restaurant reservations, launch apps, read items from the Notification Center, dictate Facebook and Twitter updates, retrieve movie reviews, detailed sports statistics, and more.

[7] A new Passbook app was added, to retrieve documents such as boarding passes, admission tickets, coupons and loyalty cards.

[5][15][16] An iOS device with Passbook can replace a physical card when scanned to process a mobile payment at participating locations.

[5][10] The App Store on iOS 6 had a brand new user interface that removed the "Categories" tab and replaced it with "Genius," Apple's search and recommendation engine.

There were also tweaks to the App Store's search algorithm, resulting in a "trend to favor newer companies," which sparked both developer concerns and praise.

[21] Upon receiving calls, iOS 6 enabled users to swipe up the lock screen to reveal "Reply with message" or "Remind me later."

[25] Reading List, a feature introduced in iOS 5, received offline support, in which text, images, and layout from saved articles get stored on the user's device.

The interface was now completely white, while the Now Playing UI was now equipped with motion sensitive scrubber bars similar to the iPod Nano 7th generation.

[30][31] Apple told The Verge that the reason for the removal was due to an expired license, but that YouTube users could still view videos through the Safari web browser.

[36] Craig Grannell of TechRadar wrote that "iOS 6 is rather like the iPhone 5 or OS X Mountain Lion - the refinement of something that already works extremely well.

Instead, each of the tweaks here will make many daily smartphone actions easier across the board and offer some relief to those waiting for certain features (sending images from email and call controls, for example).

To me, that says they may still collect your information to do things other than serve you targeted ads, like build databases about you to send you marketing or to sell to third parties.