Writing an app project brief: the questions to answer before development starts
Goals, users, features, data, integrations, security: the questions to answer when writing the project brief for your app before development begins.
5 min read
Software development · Ajaccio, Corsica
Mobile app development for iPhone and Android
Step By Step builds your iPhone and Android mobile app from its studio in Ajaccio, Corsica, either natively or cross-platform with Flutter. We design the screens, develop the app and its API, publish it on the App Store and Google Play, then keep it up to date.
- Flutter
- React Native
- iOS
- Android
- Firebase
- Supabase
- One codebase is possible
- iPhone and Android
- Syncs when back online
- Offline mode
- The right message at the right time
- Notifications
- App Store and Google Play
- Store release
Use cases
What can a mobile app do for your business?
A business mobile app serves either your customers or your teams. Either way, it replaces phone calls, paperwork and re-keying with a tool that is always at hand.
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Customer apps
Ordering, booking, loyalty, case tracking and personal accounts: a mobile app that keeps you connected to customers and saves them time.
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Field apps
Job reports, photos, signatures, readings and checklists: technicians record everything on site, even without signal, and the office gets it straight away.
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Internal apps
Rotas, expenses, leave requests and team news: the everyday tools your staff need, right in their pocket.
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Mobile version of your software
Your business software or web platform already exists: the app brings its most useful features to people on the move, through the same API.
Technology
Native, Flutter or PWA: which technology should you choose?
There are three ways to build a mobile app. The right choice depends on your use cases, your users and your budget, and we explain the trade-offs from the very first workshop.
| Approach | Principle | Strengths | Best for |
|---|---|---|---|
| Native app (Swift, Kotlin) | Two codebases, one per platform | Maximum performance, full device access | Games, highly graphical or very specific apps |
| Cross-platform app (Flutter, React Native) | A single codebase for iPhone and Android | Smooth rendering, sensors and offline mode | The vast majority of business apps |
| PWA (installable web app) | A website that installs on the home screen | No store release, limited features on iPhone | Simple internal tools, tight budgets |
Features
Features we build into your apps
A successful app makes the most of what a phone does better than a computer: camera, location, notifications and biometric sign-in.
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Secure sign-in
Password, Face ID, fingerprint or single sign-on with your company accounts.
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Offline mode
Data is stored on the device and synchronised automatically when the network comes back.
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Photos and documents
Taking photos, scanning documents, reading barcodes and QR codes.
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Location
Job locations, directions and on-site check-in, with the user’s consent.
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Push notifications
Targeted alerts for an order that is ready, an appointment or a task awaiting approval.
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In-app payments
Card, Apple Pay or Google Pay payments through a secure payment provider.
Beyond the app
A mobile app also needs a back office and an API
The app on the phone is only the visible part. Behind it, a server stores the data, manages accounts and sends notifications.
The API and database
We build the API that powers the app, on Supabase, Firebase or a dedicated Python architecture, with data hosted in France and strict access rights.
The back office
A web interface lets your teams manage content, users and orders, and follow the app’s activity through clear statistics.
Links to your software
The app exchanges data with your business software, CRM or online shop so that information is only ever entered once.
Method
The stages of your mobile app development
Mobile app development follows five stages, from scoping to post-launch support. You install test builds on your own phone throughout the project.
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Scoping
Goals, users, the features a first release really needs, technology choice and where the data will live.
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Screen design
User journeys and interactive mock-ups, tested on a phone before a single line of code is written.
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Development
App and API built side by side, with test builds installed on your own phones at every stage.
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Store release
App Store and Google Play listings, screenshots, compliance with store rules and publication.
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Ongoing support
Updates for new iOS and Android versions, fixes and new features based on user feedback.
First call on us
Got an idea for an app?
Tell us who it is for and what it should do: we will help you define a realistic first release and the right technical approach.
Development section
Our other development services
- Custom software ERP, CRM, HR, management tools: business software built around your processes.
- Web applications Portals, dashboards, SaaS: applications that run in the browser.
- Website creation Fast, well-ranked showcase websites that are easy to evolve.
- E-commerce websites Online shops connected to your till, stock and accounting.
- AI chatbots and assistants An assistant that answers from your own content, on your website or internally.
Blog
Further reading: our articles on the topic
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Flutter, React Native or native: choosing the technology for your mobile app
Flutter, React Native, Swift and Kotlin: strengths, limits and the criteria that matter when building your iPhone and Android app in 2026. A clear guide.
5 min read
FAQ
Frequently asked questions about mobile app development
Do we need separate iPhone and Android apps?
Not necessarily. With a cross-platform framework such as Flutter or React Native, one codebase produces both apps with smooth rendering and access to device features. Separate native development is mainly justified for highly graphical or very specialised apps.
How much does mobile app development cost?
The cost of a mobile app depends on the number of screens, the features (payments, offline mode, location), whether an API already exists and the back office required. We provide a quote after scoping, usually split into a first publishable release followed by improvements.
Who publishes the app on the App Store and Google Play?
We prepare and submit the app for you: listings, screenshots, privacy declarations and replies to any store review comments. The app is published under your company’s developer account, so you remain its owner.
Can a mobile app work without an internet connection?
Yes. The data needed is stored on the phone and entries are saved locally, then synchronised automatically with the server when the network returns. This is essential for teams working in areas with poor coverage.
Can a PWA replace a mobile app?
For a simple internal tool, a progressive web app can be enough: it avoids store publication and runs on every device. It is less capable on iPhone for notifications, offline use and sensor access, which is why a Flutter app is often the better choice.
Can you add artificial intelligence to a mobile app?
Yes: conversational assistants, automatic reading of photographed documents, voice transcription and natural-language search. AI processing goes through a secure server-side API, which protects access keys and controls what data is sent to the models.