Gmail

Reading through the other comments on here, it seems gmail is being used regularly and successfully.  Students are always on their phones anyway!  One idea I read that would be helpful, as a substitute, is for the teachers to email their lesson plans to the students as well.  It would avoid the "the sub didn't tell us" excuse.  Because, trust me, its just an excuse.  If its written on the teacher's lesson plan for m to assign something, I definitely do!