is the Google Authenticator saved with the google backup like wifi passwords, settings, gmail and some other google aps? If I will reflash my current system or make a clean install will it be backed up with all the codes form websites I have there? I do not want to loose it and it will be a lot of work to go to every site I have there, revoke 2step verification and then do it again with new system
Google Authenticator in version 5.00 (as of now) permits backup, but only preferences are backed up, and the critical data (secret keys which creates those codes the user need) are not backed up at all. ADB can also back it up with the command:
adb backup -keyvalue com.google.android.apps.authenticator2
I'm making this claim based on the presence of the attribute android:allowBackup set to true, and presence of key-value pairs backup provisions in its manifest and a dedicated backup agent is also listed, named com.google.android.apps.authenticator.backup.AuthenticatorBackupAgent. This certainly wasn't the case with prior versions.
Unfortunately, you can’t back up your Google Authenticator. Some services provide backup codes (such as Google Authenticator). You should save them in some safe place and use them if you lost your phone or reflash your current system. For other websites, you should save QR codes or secret keys in the process of token enrollment. If you have these QR codes you will be able to restore your tokens on any device. If you didn’t save backup codes or QR codes and lost an access to your Google Authenticator, you should contact the Support Team of services which you protect with the Google Authenticator. They will help you to restore an access to your account. Then you will be able to issue new tokens.