I'm literally only using it for things that require it. (including heroku, and rubygems). My thinking is: how do I meet this requirement with the least likelyhood of later locking myself out forever, and having HN threads blaming and shaming me for not carefully preserving my backup codes in a firesafe crypt?

If someone wants me enough to target Authy with an SMS reroute attack focused on me, they're gonna get me either way. I'm not Ed Snowden here, I'm just a guy trying not to lose his car keys.

But, what's the thing you use that provides the benefits of cloud syncing across devices and isn’t tied to a phone number? For anyone that might be interested, including me if it seems as easy and as idiot-proof. (and free or cheap).