Im middle school science teacher and absolutely love this app. Not only can I teach the planets with some basic information, but I can also talk about and show the lunar cycle! I would like an option under preferences where I can disable the camera movement. Every mouse click changes the angle, which isnt a big deal, but having the ability to disable would be fantastic. Great overall app. Well-made and authors should consider creating science apps for multiple areas: plate tectonics, such as, plate movement, boundary interactions; creating atoms with subatomic particles; so much more you all can do. Thanks for this, from an astronomy-lovin nerd. **NOTE** to the previous reviewer, and as mentioned by others previously, the circle in your menu bar at the top is the options menu for the app. Again, as another said, the black donut. Hope this helps, it sure helped me. Also, if your animation stops and your using macbook, make sure youre plugged in or that you havent selected "disable the animation when battery is in use".