Mobile App Development

The figure depends on the functional scope, the technology choice (React Native cross-platform or native iOS plus Android), the number of target platforms and the complexity of the backend (payments, notifications, geolocation, real-time chat, marketplace). A tightly scoped MVP, a full app with a backend and a complex platform involve completely different workloads. We send a detailed quote within 48 hours of receiving your written scoping brief. The quote covers design, development, testing, store release and the 30-day post-launch warranty. Apple Developer and Google Play Console fees remain payable by you, directly to the platforms.

A simple MVP in React Native ships in 3 months. A native iOS and Android app with a full backend takes 4 to 6 months. Complex projects such as marketplaces or social networks run beyond 6 months. Our agile method, in two-week sprints, means you can install and test a real build from week six via TestFlight. The precise schedule is set during the written scoping phase, with milestones and build handovers planned in advance. Timelines include design, development, testing on real devices and submission to the App Store and Play Store. Apple review adds 2 to 7 days at the end of the project.

Native Swift and Kotlin deliver the best performance, full access to the latest APIs and optimal UX. Recommended for apps with complex animations, video processing, AR or premium requirements. React Native shares 90% of the code between iOS and Android. Ideal for MVPs, startups and constrained budgets, with costs cut by 40% compared with building two native apps. We settle the question against your use case during scoping. Criteria analysed: budget, timeline, expected performance, native features required and your team's ability to maintain the app after handover.

You do. All source code is 100% yours and is delivered to a private GitHub repository that you own. No dependency on our agency. You can bring development in-house or switch providers at any time. That independence is contractual, written in black and white in the proposal. We also hand over the technical documentation, the database schema, the environment variables and access to the third-party services we configured. No in-house proprietary product, no technology lock-in. You walk away with a fully transferable technical asset.

The Apple Developer Program costs 99 dollars per year at the time of writing, and is mandatory to publish on the App Store. Google Play Developer charges 25 dollars, one time only. For apps with in-app purchases or subscriptions, Apple and Google take a 15 to 30% commission on sales. If you sell physical goods or services consumed outside the app, those commissions do not apply. Payment then goes through Stripe, with roughly 1.5% in fees at the time of writing. We help you weigh in-app purchase against external payment, based on the nature of your business and the current Apple and Google rules.

Two kinds of updates. Critical fixes are rolled out through TestFlight, then submitted to the App Store and Play Store. Apple review takes 24 to 48 hours on average. Google Play validates within a few hours. For functional improvements, we work in sprints planned according to your maintenance contract. Dynamic configuration (copy, pricing, feature flags) goes through Firebase Remote Config or Supabase, with no new store submission. That lets you change app behaviour without waiting for a review. We train your team on those tools in writing, so you are fully autonomous.

Yes. Thirty days of warranty are included in the initial engagement, covering every bug and regression found after launch. Beyond that, we offer monthly maintenance contracts. Three levels are available: essential (fixes and OS updates), standard (fixes plus 2 days of improvements per month), premium (dedicated team). These contracts include Sentry monitoring, dependency updates and annual iOS and Android compatibility work. Without maintenance, a mobile app becomes obsolete within 12 to 18 months. We always recommend a contract to protect your initial investment.

We integrate the standard services on the market. Payments: Stripe, Apple Pay, Google Pay and in-app purchase. Push notifications: Firebase Cloud Messaging and Apple Push Notification service with segmentation. Analytics: Firebase Analytics, Mixpanel, Amplitude, PostHog. Authentication: email, Google, Apple, Facebook, Face ID and Touch ID biometrics. Maps and geolocation: MapKit, Google Maps, Mapbox. Real-time chat: Stream, Sendbird or a Supabase realtime solution. CRM: HubSpot, Salesforce. Transactional email: Postmark, Resend. Every integration is documented and configured inside your own accounts, so you keep full control of your data.

TestFlight is Apple's official way to distribute a pre-production app. We invite up to 10,000 external testers by email. They install a real version of the app on their iPhone, report bugs through the TestFlight app and send feedback straight to our team. On Android, we use Google Play Internal Testing and Firebase App Distribution. The beta phase usually runs 2 to 4 weeks. It surfaces bugs in real conditions, validates the UX across devices and OS versions, and lets you prepare your launch communication. Essential before the final store submission.

Yes. GDPR compliance is built in from the design stage. Consent banner on first launch with granular tracker choices. Anonymisation of user identifiers on the analytics side. Personal data hosted in Europe via Supabase or OVH. Data export and deletion available from inside the app. Privacy policy written and linked in the app and on both stores. iOS ATT compliance (App Tracking Transparency) with the native Apple prompt. Processing documentation for your GDPR register. We work regularly with law firms in France to validate sensitive cases: health data, minors' data, geolocation.

ASO covers the techniques used to improve your app's visibility in the App Store and the Play Store. It is the app equivalent of SEO. We optimise the title (30 characters on iOS), the subtitle, the hidden keywords, the long description and the screenshots. Target queries are researched through App Store Connect Analytics and tools such as AppFollow. Screenshot visuals are designed with persuasive captions. Preview video is optional. The goal: maximise the impression to install conversion rate. Good ASO can double organic downloads with no advertising budget. An ASO audit is included in our maintenance contracts.

First contact through the website form or by email. We reply within 24 working hours. Everything is handled in writing: no calls, no meetings, no video sessions. You fill in a short written brief covering your project, your objectives and your budget range, and we come back with questions and a recommendation. That written scoping round leads to a detailed proposal with scope, schedule and a fixed engagement. No blind quoting, no surprises. Once the proposal is signed and the deposit is paid, the project starts within two weeks. Our team is based in France and works remotely with clients across Europe and beyond.