Phased release
Also called: Staged rollout
Releasing an app update to a growing percentage of users over several days, so problems can be caught before everyone has it.
Definition
On the App Store, a phased release delivers automatic updates over 7 days (1%, 2%, 5%, 10%, 20%, 50%, 100%) and can be paused; users can still update manually. Google Play's equivalent is a staged rollout with percentages you choose, which can be halted. Neither store can roll users back, so fixes ship as new versions, ideally with remote feature flags to switch off a broken feature in the meantime.
In practice
A crash appears at 5%; the team pauses the release, disables the feature remotely and submits a fix for expedited review.