What is it?Edmodo is one of the tools that I use most often with my class. Edmodo looks very similar to facebook and works in essentially the same way...except that it is totally overseen by the teacher. There are a lot of features on edmodo. Such as: posting discussions and assignments, posting grades, creating small groups & recording homework. Added bonus: it's free!
How can I use it?There are a lot of things that I like about edmodo. For starters, when the students send messages, they can only send them to the whole group (not to each other specifically) and the teacher can see everything. Also, there is a parent code which allows the parents to see their child's grades and the discussion boards that their child is a part of. In addition, the students have the potential to earn "badges" for a number of different things and this has proven to be highly motivating for the kids! I am also flipping my math classroom (for more information about that, click here) and I use edmodo as a place to post the videos for my math class.
For a wealth of information about edmodo and how to use it in your classroom, visit Richard Byrne's blog freetech4teachers. He has many, many, many resources to help you incorporate technology into your classroom!