Mobile app development services
Comtau designs, builds and releases mobile applications, along with the APIs, admin tools and integrations behind them. We work through the decisions that shape an app's cost and lifespan: platform approach, offline behaviour, sign-in, notifications, store release and the updates that follow.
Who we work with
Our custom mobile app development services are aimed at people who know what the app is for and need a team to make it reliable on real phones, in real conditions, for years.
A product where the mobile app is the main way customers buy, book, track or communicate, and where the first release has to be scoped tightly.
Field, delivery, inspection or sales teams still working from paper, shared spreadsheets or a tool that was never designed for a phone.
A platform customers already use in the browser, now needing a native companion app that shares its accounts, data and business rules.
An app in the stores that has become hard to update, after the original team moved on. See mobile app maintenance & modernization.
Product thinking
A technician finishes a job in a basement with no signal. What the app does next decides whether it gets used. We design those moments first: what is saved, what waits, and who is told.
The visit, checklist and customer details were downloaded in the morning. The app says plainly that it is offline and keeps working.
Stored on the device
Photos, notes and the customer signature are stored encrypted on the phone and queued. Nothing is lost if the app is closed.
Synced when signal returns
When the phone reconnects, the queue uploads in the background. The office gets the report, and the technician sees a confirmation.
Interface images are illustrative examples with fictional data, not client projects.
Platforms and approach
There are three sensible ways to put an app on iPhones and Android phones. The right one depends on your users, your budget and how much the app relies on each platform's own capabilities, not on which technology is fashionable.
Native mobile app development: separate apps in Swift and Kotlin, each using its platform's own toolkit and conventions.
A single Flutter or React Native codebase for both apps, with native code for features that need it.
Launch on the platform most of your users carry, then add the second once the product has proved itself.
Already decided on a framework? See Flutter app development or React Native app development.
Development scope
Scope is agreed per project. Most clients want mobile app design and development services from one team. You can also engage us for one part, such as design only, a backend for an app your team builds, or taking over a live app.
Backend and integrations
Most of what users experience as "the app" happens off the phone. Mobile app backend development services cover sign-in, the API, data, notifications and third-party services, and it is planned together with the screens rather than after them.
On the device01
Your backend02
Third-party services03
Release pathCI build & signingBeta testingStore reviewGradual rollout
A versioned API designed for mobile keeps old app versions working while new ones roll out, which matters because users update at their own pace.
Tokens live in the platform's secure storage, personal data is encrypted at rest, and sessions can be revoked from the server when a phone is lost.
Where data already lives in a CRM, ERP or billing system, the backend connects to it through API integration rather than duplicating it. Larger organizations should also see enterprise mobile apps.
Release and updates
Every release goes through the same stages, on both stores. We prepare apps for review from the first sprint, with privacy declarations, test accounts, store listings and signing in place. Then we release gradually, so a problem reaches a small share of users rather than all of them.
iPhone, iPad and Apple Watch apps
Android phones, tablets and foldables
How a project runs
Each stage ends with something you can review and decide on. From the build stage onward, that is an app on your own phone, not a status report.
Your users, goals and constraints, and an honest view on whether an app is the right answer.
Agreed next stepJourneys, platforms, data, integrations and the first release, written down together.
Scope and estimate basisKey flows as a clickable prototype, tested with people who will use the app.
Approved prototypeShort cycles with installable builds through TestFlight and Play testing tracks.
Working builds on your phoneStore submission, gradual rollout, monitoring, then the next release from real usage.
Live app and a backlogDelivery team
If you were planning to hire mobile app developers one by one, consider the alternative: a delivery team sized to the project, covering product, design, platform engineering, backend and testing. The team stays accountable for the result, not just for hours.
Team composition and engagement terms are agreed per project.
Owns scope and priorities with you, runs demos and keeps the first release focused.
Turns journeys into flows and screens that follow each platform's conventions and accessibility guidance.
iOS and Android specialists, or cross-platform engineers with native experience for the parts that need it.
Builds the API, sign-in, notifications and integrations the app depends on.
Automated tests plus testing on real devices and OS versions your users actually have.
Starting points
Mobile app development services for startups should deliver the smallest release that proves the idea, without a codebase that has to be thrown away afterwards.
For a deliberately minimal first version, see mobile app MVP development.
Companies with a live app or a web platform need the mobile work to fit what is already there.
Budget
We don't publish fixed prices. Two apps with the same label can differ several times over in effort. An estimate becomes meaningful once these factors are understood, and that is what discovery is for.
The estimate we give is tied to a written first-release scope, so you can see which decisions change it.
Each distinct flow, such as onboarding, booking, payment or reporting, adds screens, states and tests on two platforms.
One platform, a shared codebase or two native apps change the size of the engineering team and the testing effort.
An app that must work without signal needs local storage, conflict rules and background sync. Often this is the largest single item.
Whether an API exists, and how many systems the app must talk to, often outweighs the screens themselves.
Payments, health or financial data and enterprise sign-in add review, testing and documentation.
Yearly OS releases and store policy changes make maintenance a recurring cost, so plan for it from the start.
Questions
It depends on a handful of factors more than on the app's category: how many distinct user flows the first release needs, whether you need one platform or two, how much the app must do offline, how many systems it connects to, and whether a backend and admin panel have to be built as well. Two "booking apps" can differ several times over in effort.
We don't quote from a feature list alone. After a short discovery we give an estimate tied to a written first-release scope, so you can see which decisions move the number. The cost drivers above are the ones to think through first.
A focused first release is usually measured in months rather than weeks, and most of the variation comes from scope, integrations and the time needed for decisions on your side. Store review adds days, not weeks, when the app is prepared for it. We plan in short cycles with a working build you can install throughout, so progress is visible rather than reported.
Start from your users: if analytics or market data show a clear majority on one platform, launching there first is a legitimate way to learn sooner. If you need both from day one, a shared codebase often makes sense; two native apps make sense when the experience depends heavily on platform-specific capabilities. Our cross-platform app development page compares the options in detail.
Yes. Our mobile app design services can be a separate engagement: research, user flows, a clickable prototype and a design system that follows iOS and Android conventions, handed over in a form your own developers can build from. Many clients use it to test an idea with real users before committing to a build.
We recommend that you do, and we set projects up that way: the source code lives in your repository, the App Store Connect and Google Play Console accounts are registered to your organization, and signing credentials are stored in your systems. That keeps you independent of any vendor, including us. The exact terms are set in the contract.
AI tools can produce screens and simple prototypes quickly, and AI assistance speeds up parts of engineering work. A production app still needs decisions that tools don't make for you: data and offline design, security of tokens and personal data, store policy compliance, testing on real devices and a plan for updates. If an AI-generated prototype exists, it can be a useful starting point for discovery.
Rankings of mobile app development companies in the USA are a starting point, but whether you talk to a mobile app development agency or a larger mobile application development company, ask to see how they would approach your app rather than a list of logos: which platform approach they recommend and why, what they would build first, how they test on devices, who owns the store accounts, and what happens after launch. A good partner will also tell you what not to build. The answers to those questions say more than ratings do.
Tell us who will use it, what it has to do and which systems hold the data. We'll suggest a sensible first release and the approach that fits it.