Academically I can see the student work posted on the bulletin boards. Every kid in the class has a book box and they're all lined up on a shelf above the cubbies, so you can easily see what the kids are reading.
In middle school or high school? That seems odd. I don't think they even have known "reading levels" after third grade or so. Maybe this is the wrong thread.
My DS talks to his close friends about things like grades and test scores, where they were applying to college, etc., so I know some of that stuff. And it's pretty easy to observe that most teens have phones.