Apple is culling apps from the App Store
Older apps, non-functional apps and apps that don't meet Apple's new guidelines all face the chop.
Hardware aside, much of the strength of Apple’s iPhone line comes from the associated App Store that delivers everything from games to productivity apps to social media experiences, and pretty much anything else you could think of. After 8 years of existence, however, there’s little doubt that the App store is just a touch cluttered, even with Apple’s very strict controls over app submission and acceptance.
So while there’s another, slightly more hyped event happening on 7 September in the form of the iPhone 7 launch, Apple will also start seriously culling the App store on that day to remove, in its own words: "apps that no longer function as intended, don’t follow current review guidelines, or are outdated."
That means that even apps that may have passed previous Apple tests for apps could be culled, depending on how well they match up with new guidelines.
What will this mean for the apps on my iPhone?
If you have already purchased an app, or downloaded a free one, it should stay exactly as it is, even if Apple decides that it no longer meets the current guidelines in some way. That means if it’s functional it should stay functional, but if it does get culled, you wouldn’t be able to re-download it on any new iOS devices.
The idea behind the cull is to remove the many apps that relied on older iOS versions that may have become unstable, as well as to clean up app search on the App Store by ensuring that only reasonably stable apps are actually available to consumers. As such, while Apple will commence its cull on 7 September, it will do so by notifying developers that their apps are no longer compliant and giving them 30 days to fix their apps to make them compliant. If they can’t or won’t do so, that’s when they’ll be booted out of the app store.
Could I transfer a "culled" app to a new device?
Even if Apple does pull an older app that you rely on, as long as you’ve got a solid backup of your phone, preferably on a desktop machine, it should be relatively easy to transfer that app to any new iOS device you purchase.
That’s naturally dependent upon it continuing to work under new versions of iOS, such as the soon-to-be-released iOS 10, for example. If at some point it stops working due to incompatibility issues there won’t be much you can do. However, restoring from a backup, or transferring older apps via iTunes should still continue to work for the time being.