Here is a helpful discussion including using the Yubikey Neo NFC with Android phones and alternatives to Yubikey: https://news.ycombinator.com/item?id=13635433
Google 1st: https://security.stackexchange.com/questions/150153/is-a-dum...
But isn't the point of 2FA that it's OK to have each of the factors individually be (relatively) insecure—passwords being about as insecure as imagineable for most users—as long as no-one is likely to have access to both of them? Thus, it's OK if someone can read your texts, as long as they don't also know your passwords.