I just bought an iPhone 3G secondhand from a friend. Under Settings the version is listed 4.2.1 but it's missing some of the iOS 4 features. Double-clicking the home button doesn't bring up recent apps, and there's no option to set this function in the home button settings. There's also no Game Centre on the home screen. Does anyone know why this might be?

EDIT: While it will download apps requiring iOS 4.0 from the App Centre, they crash immediately after opening. Apps requiring iOS 3.0 work fine.

2 Answers 2


This is by design, although the basic internal features and functions of iOS4 are present (this is mainly the stuff that apps will use, so you can be sure that if your app says it needs OS4, then you can run it) not all the OS functions are present, and this includes the background switching functionality as well as a few other things. I can't remember them all right now, but the 3G only got some of the functionality that the iPhone 4 and 3GS got.

Likewise, when OS6 comes out later this year, there are bits and pieces that will not run on an iPhone 4, which will run fine on an iPhone 4S - I think the turn by turn navigation will not be available on the iPhone 4, for example.

This sort of thing has always happened with iOS upgrades, and the hardware at the bottom of the compatibility tree often has to forgo some of the features. Often it's down the memory constraints etc. The key is that none of the missing bits are essential for the running of other apps, so an app that needs OS4 will run fine whether or not you are running it with all the new bits, or only some of them. Apps will only care about the APIs available to them, and you should have the very same ones regardless of the extra stuff on top that is missing.

  • Thank you, that makes sense. Although apps requiring iOS 4 will NOT work, which is disappointing. (At least, none of the apps I've tested so far have worked.)
    – Pip
    Commented Jul 26, 2012 at 10:33
  • Check the apps actual compatability requirements, because some just say OS4, when they mean OS4.3, and I believe that the 3G does not go further than 4.2.1
    – stuffe
    Commented Jul 26, 2012 at 10:39
  • Nope, "4.0 or later". Apps requiring 4.3 bring up an error message and can't be downloaded; apps requiring 4.0 download but crash when I try to run them; apps requiring 3 run fine.
    – Pip
    Commented Jul 26, 2012 at 10:45
  • I think you have a subtly different issue, because you certainly should be able to run them, and I have a 3G and an old 2G iPod Touch which sit at 4.2.1 and can run them.
    – stuffe
    Commented Jul 26, 2012 at 10:54
  • That's what I thought. The whole thing seems not quite right. Thank you for your help anyway.
    – Pip
    Commented Jul 26, 2012 at 11:01

on jailbroken phones, we can actually rename the firmware version like 3.0 can be written as 4.2.1 or 5.1.1, but actually it is only 3.0 i think you have only 3.0 version.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .