http://www.educationworld.com/a_tech/instagram-classroom-student-activity-ideas.shtml has some good ideas for using Instagram in the classroom, such reacting history. I would be cautious and post that Instagram to a secure or private place or Instagram Direct too. One could also react the characters of popular books too.
Instagram Direct is a must for this educator when posting student pictures or video clips. However, like anything online, I would be cautious with copyright. Any thoughts on Instagram Direct?