iOS and Android App Build

When does a business need a mobile app?

Less often than it thinks. Most business apps, including customer portals, booking tools and dashboards, are 30–50% cheaper as web apps and work well in a browser on a phone. The web app and client portal build is the right answer for most enquiries that arrive asking for an app, and the discovery sprint will say so.

A native app is the right build when the phone is the product. The app needs the camera as its main input, must work offline on a site with no signal, depends on push notifications as the core experience, or has to be found in the app stores because that is where its users look. When one of those is true, the build is a React Native and Expo app for iOS and Android from one codebase, scoped and priced to the feature set the sprint fixes.

Why React Native and Expo?

Cross-platform is 1.1–1.3 times the cost of building for one platform. Two separate native builds, one in Swift and one in Kotlin, run 1.6–1.8 times. For a first app that has to be on both stores, that is a 30–40% saving, and it is the reason the app is built with React Native and Expo rather than as two codebases.

The result is a real app, not a website in a wrapper. It has access to the camera, the file system, notifications and offline storage, and it is submitted to both stores. One codebase also means one test suite, one CI pipeline and one set of documentation to hand over.

How is the scope fixed?

The feature set is fixed during the discovery and prototype sprint. The sprint runs two to three weeks from $4,500 + GST, credited against the build if it proceeds within 30 days, and it does the hard work of deciding what earns a place in version one. The clickable prototype goes in front of real users before the build price is fixed, so the features in the quote are the ones people actually reach for.

There is no feature cap. A larger set costs more, the quote itemises what it covers, and anything that does not make version one is recorded in the requirements as version two, priced separately once the app has real usage behind it.

What is included in every build?

Test automation and release assurance are in the price of every build above the discovery sprint. They are never an optional line and never negotiated away, and they matter more on mobile than anywhere else, because a broken release sits in a store review queue while it is fixed. Every build includes:

• An automated on-device test suite in Maestro, run on iOS and Android simulators in CI, with Detox where a flow needs gray-box control of the React Native runtime; Playwright covers the backend and the API, because it drives browsers rather than native screens
• API contract tests against every integrated service
• Rate-limit testing with K6 where third-party API caps apply
• Failure-mode coverage: token expiry, webhook retry, partial failure, duplicate delivery, and offline retry for the app
• Security checks for IDOR prevention, no client-side tokens and backend-only credential handling
• A CI pipeline on GitHub Actions with the test suite gating every release build
• Test documentation and a release runbook your next developer can actually run

The backend is built to the same standard as a client portal: OAuth 2.0 authentication, credentials held on the server and never in the app bundle, and per-record access checks.

What does an iOS and Android app cost to build and run?

Builds are priced from $18,000 + GST. A small feature set, one backend and one integration is the starting price; more screens, offline sync, a second integration or health and financial data sit above it. The price is fixed after the sprint.

Three further costs are named in every quote rather than discovered after launch. Annual maintenance runs from 15% of the build cost, so a $30,000 build carries from $4,500 a year; the app maintenance plan is quoted as a monthly line item with named inclusions and no lock-in, and covers the operating system updates and store compliance changes a mobile app cannot skip. Third-party API usage bills by volume, from around $50 a month for a quiet app to four figures monthly for a growing one. And a business turning over more than $3 million a year, or handling health information, has obligations under the Privacy Act 1988 that add 10–40% to a build depending on the data type. Every third-party platform and API fee, including the Apple and Google developer programs, is named in the quote and who pays is settled in writing before work starts.

What do you own?

Everything. The repository, the test suite, the CI configuration, the backend hosting and the Apple and Google developer accounts are in your name, and the release runbook is written so another developer can ship version two without us. A tested app is cheaper to maintain, and a client who holds the tests is never hostage to the people who wrote the app.