Apple released iOS 5.1.1, an update for the mobile operating system for iPad, iPhone, and iPod touch on Monday, May 07, 2012.

Image Credit: Apple
According to Apple official website the iOS 5.1.1 Software Update contains improvements and bug fixes:
- 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
You can install the update directly from your iOS device, if you’re running iOS 5 or later:
- Launch Settings
- tap General
- tap Software Update.
The iOS 5.1.1 upgrade is a much smaller file than iOS 5 or later