Point your iPhone at the sky and see live flight data overlaid in AR: flight number, aircraft, altitude, speed, and destination — no ARKit required.
SkySpottr turns your iPhone into a plane-spotting instrument. Point it at the sky and the app overlays live flight data on the aircraft above you: flight number, aircraft type, altitude, speed, heading, and distance — an AR reticle locks onto a plane while a data card floats beside it (one screenshot shows SWA519, a 737-700, climbing at +2880 fpm). A circular radar map at the bottom shows every tracked aircraft around you, with 50-tracked counters and heading indicators, and tabs for Spot, Leaderboard, History, and Profile give it the feel of a hobbyist's field tool rather than a toy.
The clever bit is how it works: ADS-B data projected through GPS and compass math, no ARKit required. That tradeoff is part of why the app is interesting to read about — the developer documented the whole thing on Show HN with a section called "Takeaways from vibe-coding a full product," and stated plainly: "Built an app entirely with Claude/AI assistance." Claude Opus 4.5 did the UI work; Gemini 3 cleaned up code the author described as messy.
Under the hood it's an iOS SwiftUI frontend on a self-hosted backend — Django and PostgreSQL with Redis, running on a single VPS, later partially rewritten from Python to C# for performance. It's free with a $1.99 Pro tier, and the App Store shows v1.3.3 was updated about a day ago, so this is an actively maintained product, not a one-shot demo. For aviation nerds who've ever pointed at a contrail and wondered what it was, this is the app that answers.