Perubahan iOS dari 5.0.1 ke 5.1.1,
Initial release on iPad 3rd gen.
Re-release of the WiFi only model of iPad2 (iPad2,4).
App Store download limit over 3G increased from 20 to 50 MB.
“Sleep iPod” function in clock application changed to “Stop Playing”, this function also works for applications other than Music.
Redesigned Camera app (iPad).
Camera shortcut on lock screen now always present, and has a new slide-up gesture to activate (iPhone and iPod Touch 4th generation only).
Camera face detection now highlights all detected faces (iPhone 4S only).
License column added under the About menu.
Improved Location Services.
Minor UI changes in Maps.
Fixed slowdown when changing to landscape (Cover Flow) in Music app.
Shake-to-shuffle bug fix, which previously caused the Music app to freeze.
Smart playlists bug fix.
Genius Mixes and Genius playlists for iTunes Match subscribers.
Podcast controls for playback speed and a 30 second rewind (iPad).
Baseband updates for some devices.
Carrier updates (e.g. AT&T 12.0, Verizon 12.0).
AT&T indicator now says “4G” when on HSPA+
Fixes iPhone 4S support for Caller ID Name Display (on supported carriers – e.g. Rogers & Fido in Canada).
Possible fix to Outgoing Call No Audio (OCNA) issue.
Restores the 3G switch on iPhone 4S
Combined Voice/Data Roaming Switch on iPhone.
Photos can now be deleted from Photo Stream.
Safari address bar now has “Go to this address” instead of a blank bar;
Bookmarks list no longer automatically displayed on browser opening if there are no open pages in Safari.
A string format exploit in an application named Raccon that allowed executing unsigned code at boot-up is fixed.
An ROP exploit that allowed executing payloads vnimage is now fixed.
A flaw that was executed by mounting a maliciously crafted disk image and may lead to a device shutdown or arbitrary code execution is now fixed.
A logic issue with debug system calls that could bypass sandbox restrictions is fixed.
Webkit security updates.
A format string vulnerability existed in the handling of racoon configuration files (VPN) is now fixed.
CFNetwork Security updates.
Enhanced Siri dictation support during text input “on supported devices” (iPhone 4S in 2011, The New iPad [unofficially the iPad 3] in 2012).
Japanese language support for Siri (availability may be limited during initial rollout).
Audio for TV shows and movies on iPad optimized to sound louder and clearer.
Setup Assistant bug fix.
Attempts at fixing battery life; results are mixed.
Bluetooth status bar indicator bug fix.
Improved Assistive Touch.
Fixed bug that allowed nested folders (folders within folders), including Newsstand.
Fixed bug that caused stuck keys on Apple Bluetooth Keyboards during wakeup from low power states.
Redesigned fonts for few non-Latin languages
Bug fixes, security update
Improves reliability of using HDR option for photos taken using the Lock Screen shortcut.
Addresses bugs that could prevent the new iPad from switching between 2G and 3G networks.
Fixes bugs that affected AirPlay video playback in some circumstances.
Improved reliability for syncing Safari bookmarks and Reading List.
Fixes an issue where ‘Unable to purchase’ alert could be displayed after successful purchase.
Seems to have fixed iPhone 4S Echo on calls.
Added a decline button to calls.
Podcast playback position now synced between iOS devices (presumably via iCloud).
Source : id-phone