Quote Originally Posted by Bun_Vivant View Post
Alternatively, to replace the SE app my spouse and I use Authy by Twilio on our iPhones and Apple Watches for 2FA for our FFXIV. We've got all four of our accounts on all four devices, so we can login to any account if any of the devices is available.
It's easy to install, easy to use, and free. https://authy.com/

The only issue we ever had was on a cruise through the Panama canal, where the Apple Watches apparently got confused regarding what time zone we were in and generated bad codes, but the iPhones worked just fine even in that situation.
Seconding the Authy recommendation, specifically because you can transfer it to another device without disabling, getting new device set up, reenabling.