How much does it cost to build a custom mobile app? It's the most-asked question in custom development and the most evaded by agencies. Real number: most builds in 2026 land between $25k and $250k, with the spread driven by four factors that are easy to estimate up front.
Here's the honest math.
What drives mobile app cost
1. Platform strategy
- iOS only or Android only: 50% of dual-platform cost. Choose this when you're testing market fit before going wider.
- iOS + Android via React Native or Flutter: roughly 1.3–1.5x single-platform cost. Standard for most builds in 2026.
- iOS + Android via native (Swift + Kotlin): 2x single-platform cost. Justify this only when you genuinely need native performance (games, AR, intensive animations).
2. Backend complexity
A mobile app needs a backend in 90% of cases. Auth, user data, push notifications, in-app messaging, analytics, billing, sync. The backend is often 40–60% of the cost — not the app UI itself.
3. Integrations
Each integration adds time. Payments (Stripe, Apple Pay, Google Pay) — 3–5 days each. Auth providers — 1–2 days. Maps/GPS — 3–5 days. Push notifications — 2–3 days. Backend services (CRM, ERP, accounting) — 5–10 days each.
4. Polish and native feel
A working app is different from a polished app. Custom animations, micro-interactions, haptic feedback, optimised for both phone and tablet — these add 1–3 weeks. Worth it for consumer apps, less critical for internal/B2B.
Three worked examples
Tier 1 — Operational MVP ($25k–$50k)
- Single platform (iOS or Android), or React Native cross-platform with simpler UI
- Auth, ~6 core screens, basic backend (Firebase or similar)
- 1–2 integrations (e.g., Stripe + push notifications)
- 5–8 week build
Best for: B2B internal tools, field-service apps, or first-version consumer MVPs validating market fit.
Tier 2 — Production consumer app ($60k–$130k)
- React Native or Flutter, both iOS and Android
- 15–30 screens with polished animations
- Full backend (auth, profiles, real-time data, push)
- 5–10 integrations (Stripe, social auth, maps, analytics, etc.)
- Both phone and tablet layouts
- App Store + Play Store submission with reviews handled
- 10–16 week build
Best for: consumer-facing apps with real product/market fit being scaled into production. The most common scope.
Tier 3 — Enterprise / high-performance ($150k–$300k+)
- Native iOS (Swift) + native Android (Kotlin) for performance
- 40+ screens, custom UI components, complex offline behaviour
- Multi-tier backend with real-time sync, conflict resolution, advanced analytics
- 10+ integrations including legacy enterprise systems
- Compliance work (HIPAA, SOC 2, GDPR)
- 16–26 week build
Best for: apps where performance differences are user-perceivable (games, AR/VR, intensive 3D, real-time camera/audio) or compliance is non-negotiable.
iOS vs Android vs React Native vs Flutter
For most 2026 builds:
- React Native is the default for both platforms simultaneously. Mature ecosystem, near-native performance for typical apps, single codebase.
- Flutter is a strong alternative if your team prefers Dart and pixel-perfect UI consistency matters.
- Native iOS (Swift) if your audience is 90%+ iOS or you need the highest performance ceiling.
- Native Android (Kotlin) if your audience is 90%+ Android (less common in the US, common in emerging markets).
Most teams overestimate the performance gap. For 95% of apps, React Native is indistinguishable from native to end users.
When NOT to build a mobile app
- Your users are 5–50 small business owners (build a responsive web app, way cheaper)
- You haven't validated demand for the desktop/web version yet
- Your "app" is really a wrapper around a website (PWA is sufficient, $5–15k instead of $50k)
- Apple App Store / Google Play Store submission politics worry you (PWAs avoid this entirely)
If you want a transparent cost for your specific mobile app scope, our cost calculator gives a range in 60 seconds. For the longer build-vs-buy thinking, see Custom Software vs SaaS.