Apple has released iOS 15, iPadOS 15, tvOS 15, and watchOS 8. You can obtain the first two by going to System Preferences > General Preferences > Software Update on your iPhone or iPad.
tvOS 15 adds “For All of You,” “Shared With You,” Spatial Audio, and Smart AirPod routing features, HomeKit camera enhancements. To obtain upgrade on your Apple TV set-top box, go to Settings > System > Software Updates > Update Software. Download and install the upgrade — which may take a few minutes.
watchOS 8 can be download by going to the Apple Watch app on your iPhone and selecting General > Software Update. To install the operating system update, the Apple Watch battery needs to be at least 50%, be placed on a charger, and within range of your iPhone.
Apple has also posted new HomePod 15 software to take advantage of the new iOS, iPadOS, and tvOS features. The software is installed automatically on the HomePod unless the feature is disabled, but the HomePod can also be manually updated in the Home app.
