google authenticator has some important aspects barely noone knows.
You can print out 10 security codes, that you can use without phone.
After that, you can make 10 new security codes and print out.
It is for security reasons, if the phone doesn't work.
You can run google authenticator through a pc app of the name winauth.com
If you don't have a smartphone, you can use google authenticator on pc or even in the browser (see below).
winauth.com ist open source.
google authenticator in browser, add on: