The Siri intelligent personal assistant has a more human voice and support language translation, with English, Chinese, French, German, Italian and Spanish available at launch. Siri will be able to use "on-device learning", a privacy-minded local learning technique to understand a user's behavior and interests inside different apps, to offer better suggestions and recommendations.

Praise was also directed at the App Store's redesign and the new file-management tools.

Shortly after release, it was discovered that disabling Wi-Fi and Bluetooth connections through the Control Center does not disable the respective chips in the device in order to remain functional for background connectivity, a design decision sparking criticism for "misleading" users and reducing security due to potential vulnerabilities in inactive open connections.

Further praise was directed at the redesigned Control Center offering customizable toggles, though it was criticized for lack of third-party app support, lack of Wi-Fi network selection ability and for difficult usage on small screen sizes.

Critics also noted the new augmented reality development tools, but said their impact would depend on third-party apps and how fast developers embraced them.

The i OS 11.2 update added warning messages to explain the new functions.

Two months after release, 52% of i OS devices were running i OS 11, a slower adoption rate than previous i OS versions.

Jobs launched from the UI or from the CLI are pushed into a queue in order to be processed in background.

One or several daemon processes have to be launched to execute the jobs.

This queue allows horizontal scalability of the PIM.