A year ago Google announced that Google Classroom was coming.  After more than 20 updates based on teacher request, Google has increased the mobile functionality for teachers.  Features include:
1.  Grade assignments from your phone or tablet, add private feedback to give students guidance, encouragement, constructive criticism or personalized feedback, and return the assignment.
2.  Create and edit assignments on the go, including the ability to make a copy for every student.
3.  Take a photo to create a post or assignment and easily share with the class.
4.   Both the primary and co-teachers can access all of their Classrooms through the mobile app, and now even the co-teachers have full access to the shared Classes.
5.  Teachers and students now have the ability to view and add comments to the Private Comment thread for individual students.