You can submit an assignment in Google Classroom under the "Classwork" section on the desktop site or mobile app.

How to upload a photo to Google Drive If you took your photo on a device that doesn't have access to Google Classroom, upload it to Google Drive.

I walk through how I set up and use Google Classroom to make teaching easier and more organized. I show how to create a class, invite students using a class code or email, and share assignments ...

Google built Google Classroom, its free education platform, to help teachers create assignments and simplify the distribution and grading process.

Yup, Google has just released an iOS and an Android Classroom app, and it does a couple more things other than giving you the option to take pictures of your (or your kids') assignments to submit.