"Starting February 1, 2015, new iOS apps uploaded to the App Store must include 64-bit support and be built with the iOS 8 SDK, included in Xcode 6 or later. To enable 64-bit in your project, we recommend using the default Xcode build setting of 'Standard architectures' to build a single binary with both 32-bit and 64-bit code," wrote company on its developer news portal.
Currently, developers have the option to submit 32-bit apps, but after February 1, they will have to include 64-bit support for any new apps they submit. Developers do not need to add 64-bit support to existing apps, unless they are submitting an update after February 1.
Adding 64-bit support to an app usually doesn't take too much time. Developers will have to use the most recent tools as Apple points out that the app should be built with the iOS 8 SDK. Notably, Apple will not be able to drop 32-bit support until iOS devices running on 32-bit processors are left out of the iOS update cycle.
With the introduction of 64-bit architecture with the Apple A7 chip on the iPhone 5s last year, Apple started along the path improving the overall performance of iOS devices. iOS devices running the company's 64-bit processors (Apple A7 and Apple A8) are still able to run 32-bit apps which have not been updated to include 64-bit support. With the slow transition to 64-bit, there will come a point when all the apps being used on a day-to-day basis will be 64-bit and optimised to run on the newer architecture.Last year, Apple had similarly asked developers to build apps with iOS 7 SDK and Xcode 5, seeking compatibility with the completely new interface in the new version of iOS.