There are multiple reports that allow for the monitoring of a site.  First, however, the user wishing to monitor a site needs to have an account with the role of  "principal." This will give them access to site-level reports.  All assessments and LGL Edge usage can be monitored.
From Reporting tab:
How can I check to see who has completed assessments in my class or site? - Click Here

 
From the Data Portal:
What reports are offered in the Data Portal for Teachers and Principals? - Click Here

 
Also see the tip sheet attached for detailed step-by-step instructions on the various reports that will be helpful.