Flutter App Development Services for US & EU Mobile, Web and Desktop Products

Flutter wins when pixel-perfect cross-platform UI parity matters more than feeling 100% native, when you want one team shipping iOS and Android (and web/desktop) from one repo, and when your design system is custom rather than platform-default. React Native wins when your team already lives in TypeScript and your app is mostly screens-on-top-of-APIs. Native Swift/Kotlin wins for AR/VR, deep OS integration, and apps with platform-specific UX expectations (e.g. iOS-only premium consumer apps). Kotlin Multiplatform wins when you want to share business logic but keep native UI — great for existing native teams adding code sharing without committing to one UI framework. We have shipped on all four and will tell you honestly during discovery.

Flutter 3.27 stable with Dart 3.6 as of 2026. Material 3 default for Android-leaning brands, Cupertino with adaptive widgets for iOS-leaning. Minimum supported iOS 14, Android API 24 (covers 99%+ of devices in EU and US markets). We pin Flutter SDK per-project via fvm so every contributor and CI runs the same exact build. Quarterly SDK upgrade reviews — we never sit on a Flutter version more than two minor releases behind stable in production.

Yes. Backend defaults to EU regions (AWS eu-central-1, GCP europe-west3, Supabase eu-central-1) with KMS keys held in the customer account. We ship App Store Privacy Manifests (mandatory from May 2024) declaring every required-reason API and SDK data collection. Play Data Safety section completed against the actual SDK inventory. GDPR consent via UMP (Google) or custom CMP integrated with our analytics and crash-reporting stack. Apple ATT prompt where IDFA is needed. Anonymous identifiers default, PII opt-in only.

Drift (SQLite) or Isar as the local store, with our own sync layer or PowerSync when the customer wants managed sync. Conflict resolution defaults to last-write-wins on simple records and operational transforms or CRDTs on collaborative data. Background sync via WorkManager (Android) and BGTaskScheduler (iOS) on a 15-minute cadence with exponential backoff on failure. We have shipped a field-service app that survived a 27-day offline gap (vessel at sea) and synced 14 GB of inspection data on reconnect without a single conflict requiring manual resolution.

Yes, this is a common engagement. Step 1: get the test suite green on the existing version. Step 2: complete null-safety migration (most teams stopped 80% in). Step 3: stepwise SDK upgrade 2.10 → 3.0 → 3.10 → 3.19 → 3.27 with green tests at each step. Step 4: replace deprecated APIs (RaisedButton → ElevatedButton, AccessibilityFeatures, BottomNavigationBar themes). Step 5: introduce Riverpod 2 or Bloc 8 alongside existing Provider/setState, migrate per feature. Typical 80k-LOC app takes 3 to 5 months without a feature freeze.

Flutter projects are fixed-scope and tiered by product maturity, all-in and quoted in USD. An MVP runs from $3,500 (4–8 weeks: one Flutter codebase, core flow, iOS and Android, store release); a production app from $5,800 (several features, backend integration, offline persistence, analytics); a full product from $9,200 (multiple modules, roles, external integrations, CI/CD, real-device QA); and a complex app from $11,500 (offline-first sync, native FFI plugins, payments, scale, A/B). The exact number depends on the number of features and surfaces, migration depth, native FFI plugins and compliance scope. You see the line-item budget after a free scope assessment and sign off before any code is written. NDA, DPA and IP assignment are signed before kickoff, with a CET workday and a 9 AM–1 PM ET overlap for US clients. Dedicated-team and staff options are available on request.