On the other hand, when I teach I call roll the first week of class and that's about it. If you don't show up to any of those lectures, you get an email, and if you don't reply, you get dropped a couple weeks in when the university sends instructors the form for doing that. That sorts out anyone who forgot the class, misread their schedule, switched sections and didn't say, etc. Other than that, I don't really care if you show up? Quizzes happen at scheduled times and I send a note if there's an in-class activity that's graded, but that's it. And, yeah, other than the shitty bluetooth hardware, SpotterEDU is basically selling you a fancy button that pulls router logs and dumps them into a csv. Universities love that shit, though, because it is yet another expensive data aggregation tool that provosts can use to feel important.