Updating an older iPhone to Apple’s new iOS 9.1: Here’s what you need to know

Apple released iOS 9.1, its first major point update to iOS 9. Apple typically takes a few months to put a coat of polish on its major updates, and this one is dropping unusually quickly — as the chart below shows, iOS 9.1 spent much less time in beta then any OS update since 8.1. OS 9.0 had a fairly quick turnaround as well, particularly considering that Apple promised to evaluate its performance on a wider range of devices and has gradually increased the number of products that each OS runs on.