TripBack

After
After
Before
Before
Historical Walks
Awards
Gadigal Map
Map

Inspiration

Sydney is filled with stories hiding in plain sight. We walk past old pubs, parks, buildings and street corners every day without knowing what happened there.

We built TripBack to make an ordinary walk feel like an adventure, one where the city reveals its past as you explore it.

What it does

TripBack turns your surroundings into an interactive journey through history.

As you walk, the app follows your location and notifies you when you approach an interesting place. You can discover what happened there, explore important years and see how the location may have looked at different points in time.

You can photograph the modern scene, reconstruct it in a selected historical period and compare then with now. You can also place the historical view into the real world using AR or animate it into a short, lively scene.

TripBack records your walking route, visited locations and historical creations. These become part of a personal passport showing everywhere you have travelled through time.

The app also includes a dedicated First Nations map highlighting publicly documented places connected to Aboriginal history, activism, community and living culture.

How we built it

We built TripBack as an iOS app using React Native, Expo and TypeScript.

Live GPS tracking powers a map that follows the user as they walk. Native iOS notifications alert users when they approach a nearby story and open the exact location when tapped.

We used Swift, ARKit and SceneKit to create the surface-placement experience, allowing users to position historical scenes on real walls and building facades. Walks, routes, visited places and saved creations are stored locally on the device using SQLite.

The app was built, signed and tested on a physical iPhone using Xcode and CocoaPods.

Challenges we ran into

Many of TripBack’s most important features; location tracking, the camera, notifications and AR, behave differently on a physical phone than they do in a simulator. This meant repeatedly building and installing the app on a real iPhone during development.

Creating convincing historical scenes was another challenge. The result needed to retain the user’s original viewpoint while changing anything that did not belong in the selected period.

For example, a modern whiteboard might become a chalkboard in the same position. However, if the modern building did not exist and the site was farmland at the time, the entire interior needed to become an outdoor landscape.

We also worked through background location tracking, notification deep-linking, AR surface detection, upside-down image placement and long-running video generation that needed to continue while the user explored another part of the app.

Accomplishments that we're proud of

We created a complete experience that works on a real iPhone:

A live map that follows the user’s location.
Nearby historical places that appear as the user explores.
Location-triggered notification banners.
Notifications that open the exact place being described.
Historical scene reconstruction from a photograph.
Then-and-now image comparison.
Native AR placement on walls and building facades.
Short animated historical scenes.
Recorded walks with routes and visited locations.
A personal passport of completed experiences.
A curated First Nations public-history map.
A standalone app that works without a development computer.

We are especially proud that TripBack brings all these features together without making the experience feel complicated. You can simply start walking and let the city tell you its stories.

What we learned

We learned how important physical-device testing is when building an app around the real world. Location accuracy, camera behaviour, AR tracking and notifications can only be properly understood