Kepler is an open-source application developed by programmers from around the world.

You can explore various planets and stars downloaded directly from NASA's database. It is possible to view information such as colors, measurements and age of celestial bodies.
Also bookmark your favorite objects, explore Mars rovers or view the NASA Astronomy Picture of the Day.

The application is 100% free, ad-free and is in constant development. You can view, modify or send suggestions for the app in the GitHub repository available in the settings.