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iPhone 4.0: iAds, multitasking, and 98 tweaks

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The iAd platform depends upon multitasking, and with iPhone OS 4.0, Apple will be bringing that capability to the operating system that - although it may still have "iPhone" in its name - is the basis not only for the Cupertinian smartphone, but also for the iPod touch and the iPad.

Apple is, of course, late to the multitasking party for its mobile devices. Multitasking is de rigueur in other devices such as the Palm Prē and phones based on Google's Android - although, interestingly, it isn't scheduled for the first release of Windows Phone 7.

Thursday's event being a Apple love-fest, Jobs understandably put the best possible spin on the iPhone OS's multitasking tardiness. "We weren't the first to this party," Cnet quotes him as saying, "but we're going to be the best."

Scott Forstall, Apple's head of iPhone software development, argued that the challenge in providing multitasking support for a mobile device is how to implement it without gobbling battery power and hindering performance.

Forstall was less than nit-pickingly specific about how iPhone OS 4.0 works under the hood - the event, after all, was for press and analysts, not developers - but he did enumerate a handful of new multitasking APIs that will be available to developers:

  • Fast app switching drops apps into a low-power hibernation state when they're not the primary app being used, preserving their state while they're in the background.
  • Background location uses cell-tower triangulation rather than a power-hungry GPS circuitry to supply location info to apps that don't need, for example, the highly accurate location information used by turn-by-turn navigation. Forstall used the social-networking app Loopt as an example of an app that can get by with less-specific location info.
  • VoIP calls will now be able to be sent and received while other apps are running - and even be received when the phone is in locked mode. Skype, as might have been guessed, was the go-to app for this demo.
  • Audio APIs will enable non-Apple apps to play in the background, something that only Apple's own iPod app is currently able to do - a limitation that has ticked off many a fan of Pandora Radio.
  • Local notifications will enable developers to send push notifications without having to go through Apple's servers, as they currently must. Forstall noted that Apple has sent 10 billion push notifications so far.
  • A task-completion API will enable a developer to have their app pop up an alert to inform a user when a background task has completed.

The multitasking UI is straightforward enough: a double-push on the device's Home button slips the display showing the foremost app upward, and the icons of the background apps appear below it in rows of four which can be flicked left and right. In Jobs' demo, he showed up to a dozen simultaneous background apps, but we can only assume that the number has an as-yet-unannounced upper limit.


Unlike Google's Android OS, the current iPhone OS has no concept of grouping apps into folders. For app-hungry iPhone users, this lack of heirarchical app grouping can result in home page after home page of app icons, which can make it far easier to use the iPhone's search function to track down the app you want rather than having to navigate through multiple home pages.

That will change in iPhone OS 4.0 with the addition of a folders feature charmingly named Folders. To put an app into a folder - or should that be Folder? - you perform the standard tap-and-hold app-arranging dance, but instead of moving the now-jiggling icon to a new location, you drag it over another app and they merge into a Folder.

The Folder icon changes to display apps that are in it, and it takes the name of the apps' App Store category - you can change the name, if you'd like. The new icon can be placed anywhere you choose - including the dock - and when you tap it, icons for all the apps in it appear.

Jobs didn't make it clear whether you can Folderize apps from different categories, and although he did say that you can have as many folders as you want, he didn't mention how many apps can be crammed into a single folder.

Mail and Enterprise

During his presentation, Jobs buzzed rather quickly through iPhone OS 4.0's improvements in the Mail app and in enterprise support - so much so that we're afraid we must limit ourselves to essentially repeating the bullet points from his PowerPoint Keynote presentation that describe what glories iPhone OS 4.0 will bring:


  • a unified Inbox will let you combine all your accounts into one UI, and not force you to navigate through all your accounts separately, as you must do currently
  • the ability to switch among all your accounts rather than use the unified Inbox - a feature Jobs called "fast Inbox switching"
  • support for more than one Microsoft Exchange account on the same device
  • thread-based message organization
  • improved attachment handling, using apps you have installed on your device - another benefit of multitasking


  • "even better" data protection
  • mobile device management (new frontiers in vagueness)
  • wireless app distribution
  • the aforementioned multiple Microsoft Exchange accounts
  • support for Exchange Server 2010
  • SSL VPN support

Game Center

What would any software announcement be these days without a nod to Web 2.0 and social networking? Forrstall bowed to this social dictum and introduced a new service, Game Center, that Apple will institute "later this year," apparently in an attempt to build a centralized gaming network into which all Apple mobile-game devs can link their games.

Few details were provided, but it appears that Game Center will be hub of what was described as a "social gaming network" that will allow you to invite friends to join in multiplayer games or ask to be matched up with random players you haven't met.

Leaderboards and achievement listings will also be provided, but no details were given - and Apple is looking into setting up an achievement point system à la Xbox Live.

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