We have Little SIS (as well as all the Gopher tools) from Amplified IT. Little SIS make Google Classroom management really easy, especially year end stuff. I used to use GAM but this just simplifies things.
It's been several years since I've used GAT Labs products. I liked them at the time but the decision to move to another product was made by someone other than me. GAT Labs was really good for compliance type issues. We moved to SysCloud and now moving to ManageMethods in June. Google keeps adding all kinds of new features in terms of compliance and DLP but we continue to use these security and compliance type products so we can push the alerting and reporting directly to the school admins for them to review and address instead of us in technology.