There is also microsoft authenticator which supports the same things as Google Authenticator. They just added a backup to onedrive feature too.
Do they support any other backup options? I have no interest in signing up for yet another account, just for one specific app.
Google Authenticator is essentially just RFC6238 - TOTP: Time-Based One Time Password Algorithm.
Yes
Serious question tho, can Authy be used on any website that supports Google Authenticator?