What are the concrete uses of phones in enhancing education? I've only seen

  portable calculator: fair, but why write problems that rely on calculators
  searching things up: just note it down for later
  taking pictures of slides: teacher can just post the slides

Meanwhile, there's genuine and well-founded concern that smartphones lead to firsthand and secondhand distraction, which undermines the teacher and disrupts learning. The main thing I see phones enabling is rampant social media consumption.