There's untapped magic in the gaps between gadgets. Multi-screen design is a preoccupying problem as we try to fit our content into many different screens. But as devices multiply, the new opportunity is less about designing individual screens but designing interactions BETWEEN them—often without using a screen at all. Learn to create web and app experiences that share control among multiple devices, designing not only for screens but for sensors. The technology is already here in our pockets, handbags, and living rooms. Learn how to use it right now.