Zwift for Android is currently in development. We don't have a solid release date yet, but we're targeting 2018.
While you can't currently run Zwift on your Android device, it is compatible with most newer PC, Mac, and iOS devices. Apple TV is also supported. And if you are running Zwift on one of those other devices, the Zwift Mobile Link Android companion app can also be run in tandem with it for the full Zwift experience.