My highschool technologic experience has gotten progressively less restrictive. Freshman year, if a teacher even saw your phone it was gone until after class or for the rest of the week if it'd happened before. Now, I'm typing this message on a Microsoft Surface I bought to take notes and do classwork/homework on during class. Usually on the topic of phones teachers are still kind of restrictive but during the last 10 min of class if we've finished or something they usually don't care. Plus, they don't make an effort to take away the phones, usually they'll just say "Phones away please" or something if they see one.