Convenient but annoying
I really enjoy using this tool in my classroom. The best and worst feature is the direct messaging. Since I have used it as an open forum for discussion outside of the classroom, I must also be a moderator to make sure the students were not using any inappropriate language and relevancy of the discussions. My phone can be "ping/buzz"-ing all night. High schoolers DO NOT GO TO SLEEP (>.<) (@.@) !!! *The notification can be manually turned off, which I do after a certain time.
How I Use It
I used this as a tool for sending out messages to my classes about homework, any upcoming assignments, etc. URL links can also be inserted to have students watch videos or articles to further their reading. It has been used as a forum for student's to express their thoughts and engage each other in debate outside of the classroom.