iOS 4.2.1 was released on November 22, 2010 with support for all Apple A4 devices, 3rd-, and 2nd-generation devices, with the exclusion of the Apple TV. It brings initial support of iOS 4.x to iPad, plus AirPlay and AirPrint to all compatible devices. It also contains minor changes to the YouTube app and alters the multitasking animation. On iPad, the side switch now acts only to mute system sounds. As a known major bug, this version seems to hinder the usage of the Camera Connection Kit on the iPad.
iOS 4.2.5 was released as a demo version for the CDMA version of the iPhone 4. This iPhone 4 variant was released for Verizon Wireless customers in the US on February 10, 2011, but pre-ordering was available for qualified Verizon Wireless Customers on February 3. The version released with the phone, 4.2.6, has some slight UI changes specifically for the CDMA version of the phone, including a "Personal Hotspot" switch in the Settings app, a service which has to be activated by the carrier in order for the feature to be usable. This will be able to be purchased from Verizon as a separate plan, as is currently possible on other smartphones.
iOS 4.3 beta was released to developers on January 12, 2011, and the gold master on March 3, 2011. iOS 4.3 includes finger gestures which let you switch between apps, return to then home screen, and open up the multi-tasking panel. This feature is only available to developers.
iOS 4.3 was released to the public on March 9, 2011, 2 days before the iPad 2. In addition to earlier features, the public release of iOS 4.3 includes many new features such as a Nitro JavaScript engine in Safari, making Safari run up to twice as fast.[19] iTunes Home Sharing also received a major revision in iOS 4.3; it allows users to connect to their home Wi-Fi networks and stream content from iOS devices to speakers, TVs and other devices, or vice versa.[19] Personal Hotspot for iPhone 4 is a new feature to GSM iPhones (previously released with the Verizon iPhone) that allows the user to create a Wi-Fi network with an iPhone 4 and provide Internet access for up to five other devices on Verizon Wireless, three on AT&T.[20] This will be available for both US iPhone 4 carriers, AT&T[21] and Verizon Wireless. In addition, the side button is now customizable, with users able to use it either as a system sound mute or as a screen rotation lock.[19]
iOS 4.3.1 (4.2.6 for CDMA iPhone) was released on March 25, 2011. It addressed an occasional graphics glitch on the fourth generation iPod touch, resolved bugs that were related to activating and connecting to some cellular networks, fixed image flickering when using an Apple Digital AV Adapter with some TVs, and resolved an issue authenticating with some enterprise web services.[22]
iOS 4.3.2 (4.2.7 for CDMA iPhone) was released on April 14, 2011. It fixed an issue that occasionally caused blank or frozen video during a FaceTime call, issues that prevented some international users from connecting to 3G networks on iPads, and contained the latest security updates.[23]
iOS 4.3.3 (4.2.8 for CDMA iPhone) was released on May 4, 2011 in response to the discovery of location services caching in iTunes. The update reduces the size of the cache, prevents it from being uploaded during synchronization, and erases it when location services are turned off.[24]
