How Much Does It Cost to Build a Mobile App?

The honest answer: anywhere from $15,000 to $500,000+, depending on what you're building. That's not a cop-out — it reflects real variation in scope. A focused MVP and a fully-featured consumer platform are fundamentally different products.

This guide breaks down what actually drives the price, what a realistic budget looks like for each stage, and what founders most often underestimate when planning their first app.

What drives the cost of a mobile app?

Five variables account for most of the price difference between a $15K project and a $150K one:

1. Number of platforms

Building for iOS only is the cheapest starting point. Adding Android increases cost by roughly 40–60% if you're going fully native (Swift + Kotlin). Cross-platform with Kotlin Multiplatform can reduce that premium to 20–30% while keeping native UI quality on each platform.

2. Backend complexity

Many apps need a server: user accounts, data sync, push notifications, payments. A basic backend (auth + CRUD API) adds $5K–$15K. A custom backend with real-time features, complex business logic, or third-party integrations can add $20K–$60K on its own.

3. Number of screens and flows

A focused MVP has 8–12 screens. Each screen with custom interactions, animations, or complex state takes longer to build. Apps with 30+ screens, onboarding flows, dashboards, and admin panels cost proportionally more.

4. Integrations

Connecting to third-party services — Stripe, Twilio, Mapbox, HealthKit, a CRM — each adds time. Simple integrations take a day; complex ones (payment flows with 3DS, real-time maps with custom overlays) can take a week each.

5. Design requirements

If you have brand guidelines and a Figma file ready, design time drops significantly. Starting from scratch with a full UX research phase adds $5K–$20K depending on depth.

Cost by project type

Hidden costs founders miss

• Apple Developer Program: $99/year. Google Play: one-time $25. Required to ship.
• Backend hosting: $20–$500/month depending on traffic (AWS, Railway, Supabase).
• Push notification service: free tiers exist, but volume pricing adds up.
• App Store updates after iOS/Android OS releases: plan for 1–2 maintenance rounds per year.
• User testing and beta distribution via TestFlight or Firebase App Distribution.
• App Store screenshots and preview videos — often underestimated at 2–3 days of work.

iOS vs Android vs both — which to build first?

If you're launching an MVP and budget is a constraint, start with iOS. iOS users have historically higher lifetime value and App Store review times are more predictable. You'll also get cleaner feedback from a more homogeneous device landscape.

Add Android in round two once you've validated the core product. If your target market is primarily Android (Southeast Asia, Latin America, Eastern Europe), flip that logic.

Building both from the start with Kotlin Multiplatform is a strong option when the shared business logic is complex — it amortizes the cost over time by letting you ship fixes and features to both platforms simultaneously.

How to get an accurate quote

Any agency giving you a number before understanding your product is guessing. A serious estimate requires at minimum: a list of features, target platforms, any existing backend or design assets, and a rough timeline.

The best process: a 30-minute discovery call → written spec → itemized estimate. That sequence protects you from scope creep and gives you a number you can actually hold someone to.

Summary

• MVP on one platform: $15K–$40K, 4–8 weeks.
• Full iOS + Android product: $50K–$120K, 12–20 weeks.
• Biggest cost drivers: backend complexity, number of platforms, integrations.
• Don't forget ongoing costs: hosting, developer program fees, OS update maintenance.
• Start with iOS if budget is tight; add Android after validating the product.