iOS 9 can delete and reinstall apps to make space for updates

Developers who are installing the second beta of iOS 9 have discovered a highly useful iOS 9 space management feature, which will help users who have little space on their devices install major operating system updates.

When attempting to install iOS 9 on a device with insufficient space, there's a popup that offers to temporarily delete some apps in order to make room for the update. Apps that are deleted are then reinstalled and replaced after the operating system update is completed.

Juli Clover | MacRumors