They are always on their cells or tapping away on laptops and tablets. They create and plan their social lives digitally and can find the right app for anything. But for all their perceived savvy, many teenagers haven’t begun to explore technology’s vast potential for learning. In recent years, museums, libraries, and other nonprofits have stepped into the breach, but much more can be done. In a major effort to expand the possibilities for digital learning, MacArthur and The New York Community Trust created the Hive Digital Media Learning Fund in 2010.