GDrive Sync is a private Google OAuth client used only by the owner of this site, with rclone, to access the owner's own Google Drive.
It requests access to Google Drive (scope https://www.googleapis.com/auth/drive) so that rclone can
upload, list, compare and delete the owner's own files in the owner's own Drive.
The client is not offered to anyone else. If anyone else signs in through it, it only ever acts on their own Drive, at their own request, and nothing is collected about them.
Access can be revoked at any time at myaccount.google.com/permissions.