All your messages appear when you sign into a new device with the same iMessage account.

Store your messages, photos, and other attachments in iCloud and free up space on your devices.

HomePod will automatically update to support stereo pairs, unless auto updates are disabled in the Home app.

Advanced beamforming provides wider soundstage than traditional stereo pair.

HomePod pair automatically senses its location in the room and balances the sound based on the speakers' locations.

This update supports setting up your HomePod stereo pair using your iPhone or iPad.

Take a call or play a game on your iPhone or iPad without interrupting playback on your AirPlay 2-enabled speakers.

Use your voice to control AirPlay 2-enabled speakers with Siri from your iPhone or iPad, HomePod, or Apple TV.

Control AirPlay 2-enabled speakers from Control Center, the Lock screen, or AirPlay controls within apps on your iPhone or iPad.

Play music at the same time on multiple AirPlay 2-enabled speakers in your house, all in sync.

Control your home audio system and AirPlay 2-enabled speakers throughout your house.

This update also includes bug fixes and improvements. IOS 11.4 includes AirPlay 2 multi-room audio, support for HomePod stereo pairs, and Messages in iCloud.

Download itunes version 11 .4