Class Dojo at its core is a behavior management system. It allows you to award points for positive behavior, and you can give negative points for negative behavior. This system at its core is still very valuable for high school. You as a teacher need to figure out some incentives in order to let students cash out positive points. Students still want that incentive, and if you do it the right way, they will strive for it.
Where Class Dojo is a must for high school teacher is the communication part of it. First, it allows students to receive receive a code in order to see their progress. Students can get feedback both positive and negative without having to stop instructional time. To me, that is an incredibly valuable tool. The overall best part about Class Dojo though is, that you can give PARENTS a code to see their child's behavior in real time. You can even message them from the Class Dojo app if they connect. To me, that is well worth any this is stupid comments from high school students. If little Johnny is going home and telling his mom he is awesome, you now have proof if he is not. The fact that you can now message directly from it makes it even better. You can contact the parent straight from the app instead of having to wait for a time to get on your email and look up that parents phone number.
Will there be some pushback from your high school kids? There very well could be, but I have found most accept it easily if your present it with the purpose in mind. I even acknowledge that is looks a little childish. What really makes me laugh though, is that many of those kids who claim Class Dojo is childish are the ones who are checking their profiles the most. It's also really funny to watch my higher level juniors play with the avatar. Most really love it. You can even look at most of the avatars when they are finished and say that makes since for that students personality.
Class Dojo is like any app or device, it works when you make it work. Technology will always depend on the process of implementing it. When you present it to high school kids, focus on the purpose. If you get the it's childish pushback, acknowledge it. Above all, I know Class Dojo is listening to the pushback of it's childish for high school. Liam (one of the co-founders) told me personally that they have new features coming to answer that. To me, that's the sign of an ed tech company I love, one who listens to their base users!