The substance of this film is pretty (very) boilerplate; a group of High School teens are terrorized by an unknown assailant who reveals their complicity (and some other personal secrets) after the suicide of one of their classmates. What makes it interesting is that we see everything via one computer (Mac?) screen.
This was unusual and interesting although at times a little visually over-stimulating as the users switched apps and functions as the story unfolded.
The ending was reasonably ambiguously effective, clearly setting things up for a sequel.