While the iPhone 3G can run the new iOS 4, it’s older, slower CPU is unable to take advantage of all of the new features. Some iPhone users are opting to stay with iPhone OS 3.1.3 until they upgrade to a new iPhone. If you have an original iPhone 2G, you have no choice. The new iOS 4 won’t even run on your hardware.
If you choose not to upgrade, soon you’ll be experiencing app updates that are OS 4.0 only. What do you do? Should you upgrade when iTunes or App Store show updates or should you just ignore the updates?
Until you update your iPhone 3G or 3GS to iOS 4, you’re okay updating apps. However, I think it’s better if you update on your iPhone using the App Store app only. If you update apps on your iPhone, OS3 will only let you download and update the apps that are compatible with your hardware and installed OS. It won’t let you download any apps it can’t run.
You could update your apps in iTunes on your computer but I recommend against it until you’ve updated to iOS 4 on your phone. iTunes will download all updates, even the ones that are incompatible with your phone and OS. I learned this one the hard way.
What happens if you accidentally update your apps in iTunes and download a version that’s incompatible with your phone? Not much. The new version will show up in iTunes and the old version will stay on your iPhone. When this happens, iTunes won’t overwrite the app with the phone with a version that won’t run, but you do lose the backup of the older app in iTunes.
This is more of an irritant than a problem until, for some reason, you lose the app on your iPhone — say, accidentally deleting it or having to reinstall the app. At that point, there’s almost no way to reinstall the older version of the app — it’s pretty much gone forever.
Updating what you can on your iPhone is a good idea. You’ll have the newest version of the app that you can run and you’ll probably get some cool new features in the meantime.
If you stay with iPhone OS 3 either by choice or circumstance, keep in mind that you are using an end-of-lifed operating system. Although an old iPhone is still much more useful and versatile than most new phones available, you’ll find that more and more apps will be for the newer OS only. Until you update to the newer OS, you may have to get used to seeing a constant “Updates Available” badge in iTunes.