About a year ago I wrote a post explaining why you don’t have to kill multitasking apps in iOS. iOS 4 had been introduced, bringing multitasking to iPhone, iPod touch, and iPad, and because Apple added the ability to jiggle and close them in the fast app switcher, some users decided to do just that. All. The. Time.

We’re on to iOS 5 now, we have some new players like Newsstand in the multitasking equation, and apparently the community is just as deeply divided as ever on the issue, even developers, even Apple Geniuses. So Frasier Speirs has put together a post of his own on the subject of iOS multitasking misconceptions, and while he ultimately proffers the same thesis as yours truly — you really don’t need to manually manage apps in iOS — he goes into far more detail about the whys and wherefores.

Regardless of how you feel, whether you think you should leave absolutely all task killing safely to Apple, whether you think you should purge every app, every time, or whether you’re still on the fence, take a read of Speirs’ article and give it some consideration.

Source: speirs.org

One of the most frequent questions we’re getting these days is how to close all apps at once — basically how to force quit or kill every app from the new multitasking/fast app switcher dock Apple introduced in iOS 4 for iPhone and iPod touch and iOS 4.2 for iPad.

The short answer is you don’t need to. Really. If you’ve been worried about it, relax. It’s all good.

For the long answer, read on after the break!

Multitasking is more of a marketing terms these days than a technical one. Don’t think of your iPhone as a Windows or Mac OS X machine because it’s not. It isn’t Windows Mobile or even Android either. iOS doesn’t work that way. It doesn’t (most of the time) leave a bunch of rogue processes running in the background that have to be force-quit.

iOS manages all that for you. Most applications, when you exit them, save their state and “go to sleep”. So if you were playing a game or looking at Settings and then hit the home button or switch to another app, it keeps track of where you were in the game or what page you were on in Settings, then stops the app. When you tap the icon to launch the game or Settings again, it reads the state and returns you to the same place in the app. It only seems like it was multitasking — it wasn’t. If you haven’t used an app in a long time, iOS might not even keep the saved state (you’ll notice the app re-launched and shows you a splash screen instead of going back to the last place you left it.)

This means, for most apps, you never — not ever — need to “delete” them or close them from the multitasking dock. You might feel a desire to, even an obsession to. But you really don’t need to. Really. (Breath out!)

The only exceptions are:

1. Streaming audio like Pandora. This can keep playing in the background but if you pause or turn off the music, it ends. No need to force quit these apps either. (Just check to make sure volume isn’t off, otherwise you might as well pause the music…)
2. VoIP apps like Skype. These can keep running in the background and Skype especially can drain your battery. You can close Skype or other VoIP apps if you aren’t actually waiting for a call.
3. Turn-by-turn navigation like TomTom. These can stay in the background and give you location and voice instructions and if you don’t need it anymore you can quit it to spare your battery the aGPS hit
4. Task completion, like finishing uploading a picture to Facebook or downloading your Twitter stream. These will automatically close when the activity is finished. Even if the activity doesn’t finish they’ll close after a short period of time anyway. So again, unless you really want to stop what they’re doing there’s not need to close them.

There will be rare — rare — occasions when a specific app, even an Apple app like Mail, stops working properly and a force-quit can get it to restart and behave itself. Once an a while your iPhone or iPad might get really sluggish and closing any big, recently played games might help.

But when it comes to closing ALL apps, ALL the time, just remember:

You don’t ever — never as in not ever — have to close ALL the apps in your multitasking, fast app switcher dock. It’s a sniper rifle, not a nuke. So just relax and enjoy your apps and let iOS do the heavy lifting for you.

iOS 4′s new fast app switcher interface also allows you to kill both Apple and 3rd party App Store apps that may be causing problems in the background.

To access the fast app switcher in iOS 4, double click the home button on iPhone 4 iPhone 3GS, or iPod touch G3. The interface will slide up and reveal a second dock-like set of app icons “in the background”. To kill an app, tap and hold the app until the icons begin to jiggle, then tap the minus symbol (-) at the top left corner. The app will then disappear, “deleted” from the background dock (but not from your iPhone or iPod).

This force quit or kill action will do a couple of different things depending on the type of app.

First, with built-in Apple apps, if you kill them from the fast app switcher, they will still keep running in the background. For example, if you kill Mail you will still receive Mail (it doesn’t kill the background thread that checks, sounds/vibrates, and updates the badge). Instead, it will force the background thread(s) to restart. If something isn’t working right with Mail — messages aren’t showing up properly — this is a great way to clean in out and get it going again. Likewise, it can force Safari to reload pages, iPod to fix weird behavior, and otherwise quickly handle problems that might not need a full reboot.

For App Store apps, if you kill them from the fast app switcher they will no longer function in the background. You’ll still get push notifications because those are handled by an external server, but you’ll lose things like background music playing, navigation, VoIP, and saved state (when you next launch the app, it won’t be where you left it but will relaunch from the beginning). Again, if an app is misbehaving or otherwise giving you problems, killing it can be a quick way to force a refresh without having to resort to rebooting your iPhone or iPod touch.

Remember, you don’t generally have to manage background apps in iOS 4. For apps that aren’t streaming music, location (turn-by-turn navigation), or VoIP (like Skype) you only ever need kill them if they’re obviously not working right. When it does come to streaming music, location, and VoIP, those can effect your battery life (especially background Skype right now), so you may want to keep a closer eye on them and kill them if you won’t be using them for a while.

Note: for iOS 3.x, iPhone 3G, iPod touch G2, and earlier devices, you can kill all active background tasks by holding down the sleep button until the “slide to power off” screen appears, and then holding down the home button until you’re reset to the home screen.

If you ever make use of the background app kill, let us know how it works for you. For more features, see our complete iOS 4 walkthrough.

With iPhone 1.x and 2.x, you could hold down the Home button to “force quit” an application (kill the process) and return to the Home Screen. With iPhone 3.0, however, holding down the Home button now activates Voice Control on the iPhone 3G S.

So, how do you Force Quit under iPhone 3.0? iPhonejunkie3 provides the answer (via EverythingiCafe):

To force quit an application in 3.0, press and hold the sleep/wake button until the slide to power off screen appears, then press and hold the home button until the application quits (about six seconds).

Yes, this does indeed mean holding down Home is now useless on iPhone 1.x and 2.x, but that most likely will only affect jailbreakers and others who have specific reason for not upgrading. Everyone else gets a slightly more complicated, but still functional, Force Quit.

UPDATE: Force Quit has changed in iPhone 3.0. Check out our new how-to!

Those of us who rock Mac OS X know all about the “Force Quit”. For Windows users, think killing an application via Task Manager. They’re both ways to shut down non-responsive or otherwise rogue applications from freezing us out or just slowing us down. For iPhone users, well, we don’t have to worry about that, do we? (Remember Apple mocking Windows Mobile for multitask management?)

Well, since MobileSafari, MobileMail, and other Apple apps do multitask and run in the background, it turns out we iPhone owners do still need to worry about it. And with the App Store providing all sorts of new and potentially greedy applications to strain the more limited resources of Mobile OS X, it’s certainly important functionality to have.

So what can we do? Luckily, Apple built in an solution.

Hold down the “Home” button for about 6 seconds. Your resources will then be freed up, and you’ll be dropped back to the Home Screen ready for a fresh, clean start.

Faster and easier than a full reset, it can get you out of an App jam or improve the “snappiness” of your iPhone in general.

Note: if you have tabs open in MobileSafari, the cached pages will be cleared, but fret not, MobileSafari will re-load the pages off the net for you as soon as you relaunch it.

(Thanks to Antony for the screen shots)