Two Factor Auth -> Use general available app as alternative

Hey there.
I am really happy SE has added the two factor auth to enhance security.
The only drawback is the additional app to use for it. Wouldn't it be possible to support the Google Authenticator app like Facebook, Dropbox, Github and even Wildstar do?

Maybe add it as an alternative way besides hardware token and the SE app.
that way even people without iOS or Android (read: WP8) could use this functionality.

Thanks for all the great work! :)

Added? From what I understand they had it since forever(iirc even ppl with FFXI had the hw token available)