Google certification only relates to CI Pad v3 (older v1 with Android 5.1 does not require GFS certification).

CI Pad Google Certification – manual

Troubleshooting Google Certification:

a. go to Apps, open details for Google Play Services – Storage – Clear all data;

b. go one step back, select “Permissions” give all permissions (all the listed permissions to be ticked). 

Quick video tutorial for Google Certification

Application to get GFS code (pre-installed on v3): download here

Web page to perform certification here.