Classroom for GitHub

https://classroom.github.com/

Classroom page after sign in.

You can make classroom of your organizations.
(your own organization only)

#Make classroom

This link can access invited user.
https://classroom.github.com/classrooms/17920673-treedreamer

#Create assignment

You can make assignment

1. Individual assignment
2. Group assignment

first individual assignment added.

Go to this link, show this page

If accept this,

You can see this page, and GitHub repo added to your organization.

It can be useful to programming group, study group.
I think GitHub Classroom is Good service for group.