I use Authy. Find the security good enough. As for internet access on the device, shouldn't be a problem for any site that uses TOTP. However I can't imagine a

I use Authy. Find the security good enough. As for internet access on the device, shouldn't be a problem for any site that uses TOTP. However I can't imagine a situation where the phone wouldn't have access, but I'd be accessing a resource where authentication is an issue.