Billie is an interactive lightpainting application. It allows for the creation of artwork that is fluid, reactive and shared. This device transforms light into a dynamic paintbrush, creating light features, for instance on a sphere’s surface. Billie is sensitive to all sources of light, such as a flashlight, the light of a smartphone, a candle, a lighter or any other light-emitting device. Also, by directing the source of light towards yourself, your illuminated face is replicated selfie-style onto the surface.