Multitasking has been a feature of the iPhone for years, but with the new operating system iOS4, multitasking on iPhone 3GS and iPhone 4 has never been easier. iPhone 4 comes with installed iOS4 and can be several things out of the box, but users must install 3GS iOS4 to use multitasking. Apps can also be updated to take advantage of multitasking.
How to use multitasking:
In iOS4, when you quit an app by pressing the home button, it stays in the background. Double-click the Home button (the button on the front of your iPhone) to get the programs running and it will appear at the bottom of multitasking dock. The screen will fade over time and along the bottom you will see a row of icons. Swipe your finger to scroll through the icons. Click on the application you want to go to. To shut down an application running in the background, hold your finger on one of the icons. After a skund icons begins to vibrate and the minus sign (-) displayed on them. To disable an application, click on its icon. Press the Home button to return to normal mode.
Both iPhone 3GS and iPod 4 are compatible with various iPhone accessories, such as: headsets, Bluetooth headsets, mobile cases, mobile shell. Select additional mobile accessories and begin enjoying in the rich features of iPhone 3GS and iPhone 4.