In the new Xiaomi Mi 4i, swiping from the home button to the multi tasker button gives users a smaller UI suited for single handed use. Swiping from home to back button gets the UI back to default.
Performance mode makes the user experience faster but uses up more battery than the usual. This feature can be enabled right from the notification bar.
Xiaomi Mi 4i have a smart feature that lets users kill all open apps but set some apps to be kept running even if the end all button is pressed. This is all customizable.
The Recorder app in the Xiaomi Mi 4i gives users more options to record voice, music or interview. This will be useful for certain applications where audio recording might be useful.
Xiaomi Mi 4i gives users options to suppress noise for a cleaner audio quality when making calls. This is accessible and customizable in Settings.