How to Do Multitasking on an iPhone or iPod Touch

iOS 4.0 (formerly known as iPhone OS) has a number of changes that enable you to do multitasking with certain features of your apps. The idea is to make your use of apps more intuitive and to allow you to pick up where you last left off, rather than having apps close down on you when you switch to another one. For example, you should be able to answer an SMS or call, keep a chat with a friend going and switch back to a suspended game when you're done. Or, you can click on an internet link in a mail you're reading and instead of closing your mail, it will simply take you to the internet link while leaving your mail open for switching back to once you're finished with the internet.

Apps are now viewed as "running" or "suspended", dependent on how much the memory of the iPhone can hold. While not "true" multitasking (as that would chew up the batteries), the applications are paused while some items such as music and ability to receive calls continue "running in the background".Here is how to do multitasking using the iPhone or iPod Touch.

Step

1. Familiarize yourself with switching between recently used apps quickly, without having to wait for reloading time.

• Double-tap the Home button. This will bring up the multitasking display, showing your "recently used" apps. The Home button works in a similar manner to the taskbar in Windows or the dock in Mac OS X.
• Scroll or flick right (horizontally) if you need to see more apps.
• Tap any app to reopen it. It will open instantly, and be exactly the same as when you left it if the app supports multitasking. This means your last game, search, news item, etc., will still be waiting for you to finish it (it is simply "suspended" or "frozen" until you reawaken it).

2. Close out of an app. If you don't want an app sitting around in its suspended state, you can close it. This is useful if you're concerned that the iPhone might be about to run out of memory and close down apps for you. Simply:

• Double-tap the Home button
• Scroll right across the icons to find the one you want to close
• Press and hold the icon
• Tap the red circle with a dash (the delete symbol). The app will close rather than remaining suspended.

Multitasking to try

1. Listen to audio while you continue to use another app. Audio can continue to stream while you are checking for emails, playing a game, surfing online, etc.
2. Answer your Voice-over-IP (VoIP) calls and keep doing whatever else you need to on other apps. A VoIP app ready for iOS 4 would no longer needs to be left open to receive calls; it can be left running in the background while you do other activities on the iPhone.Take the call, while continuing to use other apps. You can check your email, surf the internet, etc., while you continue to talk.
3. Use GPS with other apps running. Use the GPS app as usual, but leave your other desired apps running. For example, if you want to listen to music, you can leave the music app open at the same time as the GPS app. When the GPS app needs to tell you what to do next, the iPhone 4 will lower the music so that you can hear the GPS directions.
4. Allow uploads or downloads to complete in the background while you continue using other apps. Start the uploading or downloading process and check it's happening fine. Once you're reassured it's working, switch to another app, such as your email or playing a game, while the background task completes.

Tips

• Apps must be compatible with the iPhone for the multitasking to work. This means that the apps must be updated with the proper code. You'll know if your app is configured by whether or not it picks up from where you left off.
• You will be able to receive alerts without having to open the app providing the alerts. This will work for third party apps that provide you with alerts such as news, sports wins, weather, alarms, etc.
• A number of iOS 4 ready apps have already been submitted and approved for use, and the list will continue to grow.
• iOS 4 is not available as an update for the original iPhone or iPod Touch and multitasking is disabled on the iPhone 3G and the second generation iPod Touch due to speed issues.

Warnings

• Not all apps will be permitted to run in the background; this is a precaution to prevent draining of the battery. Music, VoIP and location-tracking devices will continue running while using another app such as listening to Pandora tunes or answering a Skype call. The other apps, however, will be "suspended" mode, easily resurrected using the double-tap on the Home key as outlined above.
• Apps are purged from the suspended state if the iPhone runs out of memory. Keep this in mind if there's something unfinished!
• Note that multitasking is still very new and there is no guarantee that your particular app will be running where you last left off.

Thing You'll need

• iPhone 3GS, iPhone 4, or the third or forth generation iPod Touch with iOS 4
• Compatible iOS 4 ready apps

Source : www.wikihow.com