With the recent release of iOS 9.0.2, Apple has finally resolved a bug that prevented developers from taking advantage of an iOS 9 feature called App Thinning. Though it hasn’t gotten a lot of press, App Thinning is a great new feature that allows developers to roll out much smaller app payloads than would ordinarily be required. And especially with Apple still selling iPhones with just 16GB of storage, anything developers can do to keep app sizes as small as possible is more than welcome.
If you’re not at all familiar with App Thinning, the way it works is as simple as it is clever. As it stands today, when developers release an app onto the App Store, the binary includes a whole lot of superfluous code to accommodate a wide range of devices, from new iPhone 6s models to 32-bit iPhone 5 devices and more. That being the case, if you happen to have an older device that can’t take advantage of more recent technologies, you’re needlessly downloading a whole lot of extra code.
With App Thinning, developers will finally be able to split up their apps so that users only spend valuable storage space on the code they actually need. Even better, developers can still just submit one app to the App Store whereupon Apple will take care of the rest.
As an illustrative example, MacRumors notes that a new iPhone 6s user “will only need to download iPhone 6s specific files, ignoring both larger iPad artwork and lower quality resources for earlier iOS devices.”
As a point of interest, Apple’s developer page advertises the feature as follows:
The App Store and operating system optimize the installation of iOS and watchOS apps by tailoring app delivery to the capabilities of the user’s particular device, with minimal footprint. This optimization, called app thinning, lets you create apps that use the most device features, occupy minimum disk space, and accommodate future updates that can be applied by Apple. Faster downloads and more space for other apps and content provides a better user experience.
Speaking to how helpful this feature will be for end users, some apps that take advantage of App Thinning will see their storage footprint reduced by as much as 40%.