And the remarkably secure telecom system, of course.
Google's style of 2FA is IMO technologically superior in that there is no communication after the initial seed. It also appears to be somewhat standardized -- see others posting about Authy. You could have your own handwritten program running the algorithm if you wanted to be independent.
The real screw up on Google's part is not instructing users to have an encrypted backup of their 2FA data.