Using a 16GB iPhone can become a challenge after a year as photos and videos take up space, apps start to pile up and the amount of free space dwindles. With earlier iOS updates even installing an upgrade on a 16GB iPhone was challenging, but with iOS 9 Apple makes two major changes that will help users who own a 16GB iPhone 6.
The iOS 8 update required 4.58GB of free space on the iPhone, but this fall the iOS 9 update will only require 1.36GB. This means it will be easier or users with a lot of apps and media to upgrade. Apple is testing an option that will temporarily remove apps for the update and add them back after installing, which could come to the final release this year.
Another option that will help those of us with a lot of apps is the ability for developers to support downloading only the parts of an app that the iPhone 6 owner needs. With this new feature the App Store will know what version you need and won't download the extra parts that don't apply to your device, using less storage overall.