How long does a mobile app take to build?
A simple mobile app (one role, basic auth, a few integrations) takes 8 to 16 weeks from signed specification to App Store / Play Store submission. Mid-complexity business apps with offline sync and multiple integrations take 16 to 32 weeks. Complex consumer or enterprise apps take 24 to 52 weeks. Add 1 to 4 weeks for App Store and Play Store review on top of the engineering timeline. Cross-platform shortens the calendar slightly; native requires two parallel codebases.
The longer answer
Mobile app timelines split into three categories driven by scope complexity, integration depth, and platform strategy. Cross-platform builds (MAUI / React Native / Flutter) compress the calendar modestly; native builds (Swift + Kotlin in two codebases) lengthen it because two codebases require two streams of engineering work.
Simple (8-16 weeks)
One user role, forms and lists, basic authentication, one or two integrations. Specification: 2-3 weeks. Build: 5-10 weeks. App Store / Play Store submission and review: 1-3 weeks. Launch and handoff: 1-2 weeks. The schedule risk is integration uncertainty — if a third-party API is undocumented or unstable, the timeline slips.
Mid-complexity (16-32 weeks)
Multi-role workflows, offline-first sync with conflict resolution, push notifications, deep linking, in-app purchases or subscriptions, several backend integrations. Specification: 4-6 weeks. Build: 10-20 weeks in two-week sprints with working demos on staging. Beta testing (TestFlight, Play Console internal testing): 2-4 weeks with real users. App Store / Play Store submission and review: 2-4 weeks total across both stores. Launch and handoff: 2-3 weeks. The schedule risk shifts from integration uncertainty to feature-scope discipline.
Complex (24-52 weeks)
Flagship consumer apps, real-time collaboration, video / audio streaming, AR / VR, marketplace apps with payments. Specification: 6-12 weeks produced collaboratively with the buyer's product and engineering teams. Build: 16-36 weeks in two-week sprints. Beta testing: 4-8 weeks with substantive user pools. App Store / Play Store submission with policy review for sensitive categories (health, finance, marketplace): 4-8 weeks because rejection-and-resubmit cycles are common at this complexity. Launch and handoff: 3-4 weeks.
What slows mobile projects down
Four predictable causes. First, App Store / Play Store policy issues — rejection cycles can each add 1-2 weeks. Second, integration discovery — surprises in third-party APIs or in the buyer's backend systems. Third, scope changes mid-build — the right fix is a written change order, not absorbing the change silently. Fourth, design iteration — mobile UI gets more iterations than web UI because users are more sensitive to mobile feel.
What speeds projects up
Pre-existing assets: a written specification that already exists (rare); a design system that already exists (rarer); a backend API that is already built and stable (relatively common for mobile companion apps to existing web products). Apps that ship as mobile companions to existing web products are usually 30-50% faster than ground-up mobile builds because the backend is already known.
Common follow-up questions
Can a mobile app launch in four weeks?
A prototype or a no-code build, yes. A production-grade native or cross-platform app with tests, App Store / Play Store review, and a written hand-off — no. Four-week mobile launches are useful for validating an idea, not for shipping production software.
Why does App Store review take so long?
Apple's review for established apps with non-controversial updates is 24-48 hours; for new app submissions or apps in policy-sensitive categories, 1-2 weeks. Rejection cycles in sensitive categories add more time. Plan launch dates with this in mind.
Can I skip beta testing?
For simple internal apps, yes. For consumer apps or apps with substantial business logic, no — the beta test catches issues the engineering team will not find in QA, and skipping it produces avoidable production incidents.
If this answer is useful and you have a real engagement in mind, the contact form routes directly to the principal — James Henderson is the single engineer who scopes, writes, and supports every engagement end-to-end.