Edmodo

    If you are a teacher and you are not using Edmodo, well, you are just  clueless.  It is the quickest, easiest way to share with students and allow the students to collaborate or share with each other.  It operates like Facebook so the learning curve for use with regards to the students could not be shorter.  I can not say it is the same for teachers.
   
   File sharing is probably the best feature for me so far.  Since I am trying the flipped classroom the students have easy access to power points, screencasts, podcasts, documents and links to webpages and videos.  After a little practice it is so easy.  You can even administer quizzes and it not only grades it for you but will break down the most missed, etc.  Just amazing!!