As spotted by a Reddit user, those attempting to download apps not supported by the iOS version running on the device will be prompted to download the "last compatible version" of the release in question.
Apps of old
Of course, many of the apps in question haven't been updated for well over a year.
Older devices, such as the iPhone 3G, weren't able to update to iOS 5. As such, while they may be compatible with the handset, new features or added modes may be missing in action.
The exact number of people likely to see these messages, however, is likely to be small, it least in comparison to those running more recent versions of iOS.
Stats pushed out by Chitaka last week suggest that only 7 percent of users are running a version of iOS older than iOS 6.
[source: Engadget]