How To iPhone & iPod iOS 4: The Basics Everything you need to know about iOS 4 Share Pin Email Print image credit: Justin Sullivan/Staff/Getty Images News iPhone & iPod Key Concepts Basics Installing & Upgrading Guides & Tutorials Tips & Tricks Switching from Android to iPhone by Sam Costello Sam Costello has been writing about tech since 2000. His writing has appeared in publications such as CNN.com, PC World, InfoWord, and many others. Updated September 05, 2018 Whenever a new version of the iOS is released, iPhone, iPod touch, and iPad owners rush to install it so their devices can get all the new features, bug fixes, and improvements that come with a new operating system. Rushing isn't always wise, though. Sometimes, like in the case of the iPhone 3G and iOS 4, it pays to research other people's experiences before you upgrade so that you don't have any problems. In this article, you can learn about the problems that iPhone 3G owners had with iOS 4, plus all of the features that iOS 4 delivered to Apple devices, and much more. iOS 4 Compatible Apple Devices The Apple devices that can run iOS 4 are: iPhone iPod touch iPad iPhone 4 4th gen. iPod touch iPad 2 iPhone 3GS 3rd gen. iPod touch 1st gen. iPad iPhone 3G1 2nd gen. iPod touch 1The iPhone 3G does not support FaceTime, Game Center, multitasking, and home screen wallpapers. If your device is not on this list, it can't run iOS 4. What's notable about this is that both the original iPhone and 1st gen. iPod touch are missing from the list. This was the first instance in which Apple dropped support for previous models when releasing a new version of the iOS. That became common practice for a few versions, but by iOS 9 and 10, support for older models became extensive. Later iOS 4 Releases Apple released 11 updates to iOS 4. With the release of iOS 4.2.1, support was dropped for the iPhone 3G and 2nd gen. iPod touch. All other versions of the OS supported the other models in the table above. Notable feature additions in later releases included 4.1, which introduced Game Center, and 4.2.5, which delivered the Personal Hotspot feature to iPhones used on the Verizon network. For full details on the release history of the iOS, check out iPhone Firmware & iOS History. The Debut of the "iOS" Name IOS 4 was also notable because it was the first version of the software to carry the "iOS" name. Prior to this, Apple had only referred to the software as the "iPhone OS." That name change has been maintained ever since and has since been applied to other Apple products: Mac OS X became macOS, and the company has also released watchOS for the Apple Watch and tvOS for the Apple TV. Key iOS 4 Features A number of features that are now taken for granted as part of the iPhone experience—such as FaceTime, app folders and multitasking—debuted in iOS 4. In addition to those, among the most important new features delivered in iOS 4 were: FaceTime video callingApp foldersMultitaskingSystem-wide spellcheck Custom wallpapersUnified inbox in Mail appiBooks app Game CenterFind text on page in Safari. Uncertainty About Upgrading the iPhone 3G to iOS 4 While iOS 4 technically can be run on the iPhone 3G, many users who installed the upgrade on that device had negative experiences. In addition to the unsupported features mentioned earlier, iPhone 3G owners ran into problems with iOS 4 including slow performance and excessive battery drain. The problems were initially so bad that many observers counseled users not to upgrade their iPhone 3G phones and a lawsuit was even filed. Ultimately Apple released updates to the OS that improved performance on the iPhone 3G. iOS 4 Release History iOS 4.3.5 release: July 25, 2011iOS 4.3.4 release: July 15, 2011iOS 4.3.3 release: May 4, 2011iOS 4.3.2 release: April 14, 2011iOS 4.3.1 release: March 25, 2011iOS 4.3 release: March 4, 2011iOS 4.2.5 release: Jan. 11, 2011iOS 4.2.1 release: Nov. 22, 2010iOS 4.1 release: Sept. 8, 2010iOS 4.0.2 release: Aug. 11, 2010iOS 4.0.1 release: July 15, 2010iOS 4 release: June 21, 2010 iOS 5 was released on Oct. 12, 2011. Continue Reading Everything You Need to Know About iOS 5 Everything You Need to Know About iOS 6 Everything You Need to Know About iOS 10 Everything You Need to Know About iOS 7 Everything You Need to Know About iOS 9 Everything You Need to Know About iOS 11 iOS: A Complete Version History Should You Upgrade Your iPhone 4 to iOS 7? Everything You Need to Know About iOS 8 Apps Missing From Your iPhone? How to Get Them Back iOS 11 Killing Your Battery? Here's How to Fix It Does FaceTime Work on the iPhone 3GS & iPhone 3G? All About Apple's iPod touch, Model By Model iOS 13: What You Need to Know Download Manuals for Every iPad Model Here Is Personal Hotspot Missing From Your iPhone? Fix It.