How Much Does It Cost to Build a Mobile App?

An app estimate delivered as one number without assumptions attached is a guess, not a plan. Two teams can describe the same product and receive quotes that differ by a factor of five, because cost follows the decisions buried in the request: how many platforms must ship, how much of the interface is custom, which outside services the app talks to, how thoroughly releases are tested, and who keeps the thing alive after launch. Pricing those decisions separately is what turns a number into something you can negotiate, compare, and hold a vendor to.

Platform count is the first multiplier. Shipping a true native app on iOS and Android means two codebases, two release pipelines, and two sets of platform conventions to respect. A cross-platform framework can share a large share of screens and business logic, but the share is not unlimited: device capabilities, performance-sensitive screens, and vendor SDKs often need platform-specific work anyway. Teams that launch on one platform first usually spend less up front, but they should assume a second build unless the architecture was chosen with sharing in mind from the first commit.

Accounts and infrastructure are small line items that still need a home in the budget. Apple's developer program is an annual membership and Google Play carries a one-time registration fee, and both tie the app to an organization that has to stay in good standing. A backend, database, file storage, and push service bill monthly whether or not anyone opens the app. Third-party services for authentication, analytics, crash reporting, payments, and maps usually begin on free tiers and switch to usage pricing as traffic grows, so an honest estimate lists which services scale with usage and who holds the billing relationship.

Design depth changes the number more than most founders expect. A build that needs a handful of screen mockups is a different project from one that needs user research, flow diagrams, a component library, empty and error states, accessibility requirements, and a clickable prototype to validate before engineering starts. Every additional state a screen can show — loading, offline, failed payment, expired session — is design work and build work at the same time. Skipping that definition does not remove the cost; it moves it into late-stage rework that is harder to schedule and easier to blame on the developer.

Engineering effort concentrates wherever the app meets the real world. Authentication and session handling, offline behavior, push notifications, subscriptions and payment rules, deep links, admin tools, and integrations with a CRM or ERP each carry their own contract, error handling, and testing story. An integration that looks like a checkbox in a proposal is often a week of work once sandbox limits, webhooks, and retry behavior are handled properly. Ask for an integration inventory with named systems, because that list is usually where competing quotes quietly diverge from one another.

Quality assurance is a scope item, not a phase that absorbs whatever time remains. A defensible QA pass covers a device matrix across screen sizes and OS versions, weak network conditions, interrupted flows such as a call arriving mid-checkout, permission denials, and accessibility basics like screen reader labels and touch target sizes. Automated tests pay for themselves on the paths that must never break, such as login and payment, while exploratory testing finds the odd states users reach in practice. The narrower the device list, the cheaper the pass, but the risk simply moves to your users.

Store review adds work that is easy to underestimate. App Store and Play submissions need metadata, screenshots at several required sizes, privacy disclosures, review notes, and demo credentials when the app sits behind a login. Reviewers can reject a build for crashes, placeholder content, or a sign-in wall they cannot pass, and each rejection costs a cycle of calendar time rather than engineering time. A release plan should treat the first submission as a rehearsal: submit early, expect feedback, and keep a buffer before any date that matters commercially.

The costs that outlive launch deserve their own line. Operating systems update every year, store policies change, dependencies deprecate, and third-party SDKs require new versions to keep working. Crash reports need triage, certificates and keys need rotation, and user support does not stop at release. A maintenance budget — expressed as hours per month or a retainer, not a vague promise — is what keeps a shipped app installable and secure two years later. Apps without that budget do not stay static; they slowly stop working as the ecosystem moves past them.

When you request estimates, ask for the same shape from every vendor: scope broken into platforms, design, integrations, backend, QA, and launch support, plus assumptions, exclusions, and the process for changes. Confirm who owns the developer accounts, the source code, and the store listings at the end of the engagement, because leaving those with a vendor creates its own exit cost. The lowest number is rarely the cheapest project; the clearest scope usually is.