Twitter has finally begun allowing users to use 3rd party two factor authentication apps to verify their identity. The new feature is rolling out to users accounts online and you can now select the default SMS authentication or a 3rd party authentication tool.
In April, the social micro blogging site rolled out SMS authentication that allowed users to have an authentication code texted to them when they were logging into their account. That is still enabled by default but you now have the option to use a 3rd party app like Google Authenticator to verify your identity. The feature requires that you log into your Twitter account online, then go to Settings & Privacy in your account settings. There you can setup an authentication app.
The SMS authentication will remain enabled by default but you can disable it once you have the new 3rd party authentication enabled.
For those that are not familiar, two factor authentication requires that you verify your identity with two pieces of information, not just your password. This makes it much harder for someone to steal your credentials and log into your account. While it is not convenient, having two factor enabled on all of your accounts lowers your risk of being hacked.