I like that they aren't providing a phone number as a backup. There has been a lot of discussion recently questioning SMS-based 2FA as a target for social engineering (and other attacks).
Thanks. Phone number backups are hard to set up and there are concerns about the security. That is why we have not build support for it. BTW I recommend using 1password so that you don't have to reset 2FA when you move phones (like with Google Authenticator).
Another great alternative in the 2FA client space is Authy (free of charge).
Another vote for 1Password. Oh and they now have a $3/mo subscription model which is pretty rad.