Across Us

See you somewhere.

Friends’ cities, overlapping plans and group trips, in one quiet iPhone app.

English · 简体中文

200+ cities, each with its own emblem.

Friends move.

Across Us keeps their cities, plans and flights in one place, so a chance to meet doesn’t slip past. No live map, no GPS trail: just the city each friend chose to share, and when they shared it.

Everyone lands together.

Invite friends to a Trip and watch every flight land where you’re meeting.

• Every flight, one tap away. Tap anyone for their boarding pass: local times, terminal and the flight home. Each traveler manages their own.
• A nudge when it helps. Flight-change alerts, morning reminders, and a tap to remind a friend who hasn’t added their flight.
• Room for plans to change. Members can leave; the creator can remove members or delete the Trip.

On your Home Screen.

Private by design.

Full policy: acrossus.app/privacy

Free, and personal.

I built Across Us for me and my friends: scattered across cities, always trying to line up the next visit. It’s entirely free. No subscription, no ads, nothing to unlock. Just a quieter way to keep up with each other, and to meet again.

For me and my friends. For you and yours.

— Yang, who made Across Us

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Under the hood

Layer	Stack
App	SwiftUI · WidgetKit (small, medium, large) · iOS 18+ · English and 简体中文
Backend	Supabase Postgres with versioned migrations · Edge Functions: api, push-worker, trip-worker, ops-monitor
Notifications	APNs, delivered per device from an outbox with retries
Flights	AeroDataBox lookups and status refresh
Web	acrossus.app on Cloudflare Pages, with Pages Functions for invite links and Universal Links
CI	GitHub Actions: backend tests, Debug / Staging / Release builds, unit tests

WhereIsMyFriend/          SwiftUI app: App, Core, Features (Friends, Trips, TravelPlans, …)
WhereIsMyFriendWidget/    WidgetKit extension
WhereIsMyFriendTests/     Unit tests
WhereIsMyFriendUITests/   UI tests
supabase/                 Migrations, Edge Functions, seed, backend tests
site/  functions/         acrossus.app and its Pages Functions
docs/                     Design spec, API contract, release notes, reviews

Run it locally

You’ll need Xcode 27 (iOS 27 SDK). The app deploys to iOS 18 and later.

1. Open WhereIsMyFriend.xcodeproj.
2. Pick the WhereIsMyFriend scheme and any iPhone simulator.
3. Build and run.

Debug builds run on a local demo repository, so the whole app works without a server. Pass -useRemoteAPI to talk to a configured backend instead.

npm ci && npm run backend:test

xcodebuild -project WhereIsMyFriend.xcodeproj -scheme WhereIsMyFriend \
  -sdk iphonesimulator -destination 'generic/platform=iOS Simulator' \
  CODE_SIGNING_ALLOWED=NO build

• Design spec
• Client architecture decision
• REST API contract
• Database schema
• Supabase production plan
• Optional local Supabase backend
• TestFlight release
• Product plan

Your friends are out there. Make room for the next hello.

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© 2026 Across Us