01 / OVERVIEW
A transit companion, not a transit authority.
Just-Go is an open-source SwiftUI app for iPhone and iPad. It plans journeys across bundled metro networks, uses Apple Maps for places and first/last-mile legs, and adds reviewed station information without pretending every city has the same coverage.
02 / WHAT CHANGED
Round 36 makes local data useful.
Home and Work remain single-slot. Custom station or map-place tags no longer have a three-tag cap.
Search the selected network or MapKit, add a tag, rename it, or remove it from one place.
Beijing operator results can use a labeled, device-only last-good snapshot when the provider is unavailable.
Clear Cache removes downloaded data and response caches without removing tags, trips, records, or settings.
All 58 catalog cities now have one versioned document plus a SHA-256 integrity index.
The product, project, target, display name, and repository now use the same name.
03 / ROUTING
From a place to a journey.
Search with Apple Maps, use the current location, tap the map, or start from a Quick Tag.
The app finds a qualifying metro network for both endpoints instead of locking the rider to the nearest city.
Walking, cycling, driving, and rail legs remain distinct. Rail lines follow their actual track geometry.
Reviewed station data may add exits, facilities, first/last trains, or live arrivals. Missing fields remain missing.
04 / DATA LAYERS
Four layers, four promises.
| Layer | What it contains | What the label means |
|---|---|---|
| Bundled networks | 53 city graphs and track geometry. | Available with the app; no operator request is needed to decode the network. |
| Station packs | 14 cities and 2,849 matched records. | Only present fields are claimed. Coverage is counted per field. |
| Official station information | Five reviewed source recipes and 1,598 station references. | Mainland operator content is fetched on the device and is not re-hosted by Just-Go. |
| External resources | 770 reviewed links across 698 unique targets. | A link is metadata, not bundled page, PDF, image, or map content. |
A stored operator snapshot is labeled as saved on the device and includes its update age. Contract or identity failures never fall back to stale content.
05 / QUICK TAGS
Any place you use often.
Quick Tags are device-local shortcuts for planner inputs. They can point to stations or arbitrary MapKit places.
- Home and WorkEach has one slot. Saving a new one replaces the previous location.
- Custom tagsUnlimited, with a rider-chosen label.
- Legacy dataExisting stored station tags keep decoding after the new place fields were added.
- PrivacyNo account or synchronization service receives a tag.
06 / KNOWN LIMITS
What Just-Go does not claim.
- No indoor-navigation runtimeNo schematic walkthrough, camera checkpoint scanner, verified indoor path, boarding-zone guidance, or door guidance is shipped.
- No community backendShared rider reports and photos are a plan, not a current feature.
- No hosted data proxyThe Station Information API is a static contract. Clients fetch permitted operator sources themselves.
- No safety guaranteeAlways follow operator notices, station signage, staff, and emergency authorities.
07 / SOURCE
Read the exact implementation.
This documentation tracks merged PR #21 at commit fc4bce3. The source is MIT-licensed; third-party data keeps its own licenses and attribution requirements.