One nifty feature on the Apple Watch is the Remote app, which lets you control media playback for your iTunes library, or on an Apple TV.
To start using this, you may need to add devices to your Apple Watch. (Mine already display on my watch, presumably because I’ve used the iOS Remote app in the past.) To do this, tap Add Device. If you already see devices, and want to add new ones, scroll down in the device list to see the Add Device button.
When you do this, the Remote app displays a 4-digit code, and instructs you to check in iTunes for a Remote icon.
Find the Remote icon at the right of the navigation bar:
Click that icon, and enter the 4-digit code.
Now you can start controlling iTunes, or your Apple TV, from your wrist. Here’s what you see:
To control music playback, you can tap the play/pause button, the next or previous buttons, and you can control the volume, by tapping — or +. You can also use the digital crown to control the volume.
If you force touch the Apple Watch display while the Remote app is visible – press and hold until you feel haptic feedback – you can access an AirPlay menu. Tap AirPlay, and you’ll see all available devices.
Tap one of them to select where you want your music to play.