Another idea is with the ClassDojo app. While it may come off as a little childish, it can be incredibly useful for a particularly rowdy class to give positive feedback. Teachers can add points to students who are staying on task or working diligently, but can also take away points for different reasons (such as off-task behavior). Students can view as points are added and will get notifications that they've done well. Teachers can also keep track of attendance on the site as well.