Updated: Dec 1, 2020
You can use the Google Classroom app on your mobile device to keep track of assignments and view returned or missing assignments.
Google Classroom app is free and available for both iPhone/iPad and Android devices.
The huge advantage using Google Classroom app gives you is that you get notifications on your device when an assignment is returned, the teacher sends a message on it, and when it's graded. I basically have real-time information about all my kids' assignments.
Launch Google Classroom.
Sign in as your child.
Enter the classroom.
Go to Classwork.
Browse or look at My work (the top right corner--icon of a person).
Filter again by assigned, returned, or missing.