The Constellation apps let you view constellations and different space objects. They also provide information about different constellations. The features that the Constellation apps provide are also available in some of the Planetarium software. We have listed some best free Planetarium software in this article. You can download them to study Constellations. If we talk about the best Constellation app, every software has its own pros and cons. Hence, it depends on the user what features of the software make it the best for him.