I was thinking on use the phone app. But I only read bad things. For example, you account can be blocked if you change your IP. I have dynamic IP, so my security token won't work every time I change IP (like rebooting router for example). I appreciate the extra security, but this should work in another way. People can lost their code or have problems with ISP and that. The system still not think in that. I am not using it, despite I want, because I don't want to get my account block for one of this causes.