Many people were complaining that there was no Authenticator for Android devices. Those complaints have not been lost on deaf ears and Blizzard has released a free download of the authenticator via the Android Market. It is the same as the iPhone and it takes hardly any time to associate the device to our account and when we enter we will have our Core Can!
If you have any questions, visit this Blizzard support article (English en).
If you have your phone next to it, You can scan the code directly!
Remember that with the Authenticator, we drastically reduce the chances of our account being stolen by any method.