Horizon is a free, AI-powered overlay app for macOS that understands what’s on your screen in real time—no copy-pasting, no switching apps. Whether you're in a meeting, reading an article, or writing code, Horizon instantly generates smart summaries, contextual answers, and organized notes, right on top of whatever you’re doing. It's like having a second brain that works quietly in the background—helping you stay focused, informed, and productive. Built by Constella App, Inc. and fully open-source, Horizon brings cutting-edge screen intelligence to your Mac—beautifully, privately, and for free.