You can use the iOS Remote app to control the music in a zone on any iOS device. Once you've downloaded the Soundtrack Remote from App Store, you need to enter your remote code. Each zone has a unique remote code. Here's how to get it:

1. Log in to your account here and go to zones.
2. Click on the name of the zone in which you want to use the remote. 
3. Click on remote to find the remote code for this specific zone.

4. Enter the remote code in the Soundtrack Remote. Now you're all set! Learn more about how to use the Soundtrack Remote app here.

Note: The iOS Remote app is not available with Sonos. You can learn how to play music from Soundtrack with Sonos here.