“Gravilux” allows for drawing with stars, being a combination of painting, animation, art, science, and game. When the screen is touched, gravity draws a simulation of stars on the tip of the fingers. One can turn and play with the particles in galaxies or explode them like supernovas. One can color the stars with their velocity and play a back musical track. In touching the end of the screen, one can change the parameters, including gravity and the number of stars, besides allowing antigravity, color, music, and uploading for the Facebook. The app allows for the simultaneous collaboration or competition among many users.