The Nexus Q app runs on any phone or tablet running Android system version 2.3.3 or later. You can use it with current versions of Google Play and YouTube apps to stream music, TV shows, videos, and HD movies to Nexus Q devices that are set up in your home. After you install and open the Nexus Q app, the Google Play and YouTube apps on your phone or tablet will offer a new feature to stream entertainment through Nexus Q.
Each Nexus Q device is designed to control the equipment in one room: speakers, AV systems, TVs, and more. Each room with a Nexus Q appears in the Nexus Q app, where you can control what's playing and at what volume, or (for music only) stream to multiple rooms at the same time.
And when friends come to visit, they can also use the Nexus Q app to stream any of their own music or movies from Google Play through your Nexus Qs, using their own Android phones or tablets.
So you don't need a Nexus Q device to use the Nexus Q app. You just need a friend who has at least one Nexus Q and will let you stream your own music, movies, and TV shows through it.