Furthermore, Apple says that beginning June 1, 2015, existing apps on the App Store will need to be updated by developers with 64-bit support and be built with the iOS 8 SDK, or they’ll be suspended from the App Store.
Apple brought 64-bit support to the iPhone 5s in 2013, and of course extended it to the iPad, iPhone 6, and iPhone 6 Plus. The iPhone 5c is the only current device in Apple’s lineup to not see the performance benefit of a 64-bit chip architecture.