I'm pretty sure you could always manually export a QR code for every one of your secret keys.
This was around 2016 and that was not an option at the time.
edit: the app used to be open source: https://github.com/google/google-authenticator-android/
"By design, there are no account backups in any of the apps."
alt Hacker News
This was around 2016 and that was not an option at the time.
edit: the app used to be open source: https://github.com/google/google-authenticator-android/
"By design, there are no account backups in any of the apps."