Works with CiviCRM 4.6. It might not be supported anymore.
This CiviCRM extension provides one way synchronisation between CiviCRM groups and Google Groups.
Since CiviCRM 5.x, extension releases compatible with CiviCRM 5.0 are compatible with 5.0 and later. An extension release compatible with 5.25, for example, means that it requires CiviCRM 5.25 or later.