Board Thread:Game Discussion/@comment-32019651-20190207160951/@comment-33870577-20190207175745

"Google+ Migration Google+ is moving to Google Play Services. Android players should not need to make any changes to their cloud saving option, as the migration will happen automatically. To ensure a safe transition, have your save game backed up to the cloud, and do not uninstall the game prior to updating. We recommend recording your Player and Device ID as a safety precaution should you need to contact support. iOS players who use Google+ will need to use an alternate cloud saving option (e.g. Game Center, or Facebook). We will remove the Google connect button completely for iOS users in a future update. For more information about the Google+ Deprecation, see here."

(link)