Yellow Car Street

The task

There is a family game: whoever first spots a yellow car in the street shouts “YELLOW CAR!” and punches the neighbour in the shoulder. I wanted to take it to the phone and to friends who live far away: you send a friend a little yellow car with a gift in the trunk, and it really drives to them, on real roads, in real time.

Role

Idea, design, development, backend, App Store release

What I did

• Design and development for iPhone: pick a friend, put a note, a photo or something from your chest in the trunk, and the car drives the whole way by itself. It refuels, waits for ferries and sometimes breaks down. You follow it on the map and your friend sees it coming.
• The route is real: it is calculated on my own routing server from OpenStreetMap and played out in advance at a real speed. For friends in Ukraine the car can also go by train via Przemyśl, by courier or by post through the sorting centre in Kyiv.
• A trunk with a life of its own: on arrival the friend opens it and has a day to reply, then the car drives home with what they packed. Ice melts on the way, bananas turn black and a souvenir appears at the first border. A car can be lost for good, with its trunk.
• The “YELLOW CAR!” button: spot a real yellow car in the street and press it. Whoever of your friends is first gives a “punch”, and the points count for the whole week. A friend’s car driving through your town counts, too.
• Pixel cars, items and scenes of my own design. A backend on Cloudflare, sign-in with Apple or an email code, push notifications, friends by invitation only, so nobody sees more than your city. The interface in English, German and Ukrainian, the landing page and everything for the App Store release.

Result

Released on the App Store on 5 November 2026. One car is free, the others can be bought, with no ads.

Built with

Swift, SwiftUI, MapKit, App Intents, WidgetKit, StoreKit · Cloudflare Workers, D1 · Valhalla, OpenStreetMap