Flyby - Spot launches and satellites overhead, in AR.

Hey Product Hunt! Maker here. Quick story on why Flyby exists. We've been building space software since 2019 (our previous app was Space Tracker), and we still kept missing rocket launches and bright satellite passes happening right over our heads. A Falcon 9 would lift off from the Cape, and someone on Twitter would post a photo of the exhaust plume from their backyard 200 miles away. We'd think, wait, we could have seen that? Turns out the apps that are supposed to help you follow this stuff don't actually help you see any of it. Launch trackers give you a countdown and a YouTube embed. Satellite trackers happily tell you the ISS is "overhead" at 9:47 PM, but not whether the sun angle, your light pollution, or the satellite's actual brightness make it visible from where you're standing. So we built the app we wanted. Both of us are software engineers with aerospace backgrounds (one of us worked on Artemis), so we got obsessive about the visibility math. Flyby runs full calculations: orbital geometry, solar illumination, atmospheric conditions, satellite magnitude, your local light pollution. You only get notified for passes that are genuinely worth going outside for. For launches, we compute exact T+ windows for when the vehicle enters your line of sight from your location, which direction to face, and how high to look. Open the app, point your phone at the sky, and AR puts a marker on whatever you're trying to spot. A few other things we're proud of: - Real-time ascent simulations with haptic liftoff, stage separations, and live telemetry on a 3D globe - Live Activities on the lock screen and Dynamic Island for both launches and passes - Customizable notifications by agency or company We'd love your feedback, especially if you've used other space apps and have opinions on what they get wrong. Happy to answer anything!