App development company in Paris
Mobile app development for Paris companies: iOS, Android and web apps in French and English, designed with care and released to the App Store and Google Play.
- Custom quote after a brief
- No sales pitch
Company-wide:★★★★★ 4.9+ on Clutch·250+ brands·10 offices
UnFoldMart is a mobile app development agency with an office at 75 Avenue de la Grande Armée, 75016 Paris. We design and build iOS, Android, cross-platform (Flutter, React Native) and web apps for Paris companies, in French and English, with the GDPR and CNIL guidance planned in, from discovery to store release and support. Meetings with Paris clients are by video in English, and pricing is a custom quote after a short brief and a free 30-minute call.
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Key facts
| Service | Mobile and web app development: iOS, Android, cross-platform (Flutter, React Native), web apps and PWAs, backend and store release |
|---|---|
| Company | UnFoldMart |
| Office | 75 Avenue de la Grande Armée, 75016 Paris, France |
| Meetings | By video (in-person meetings only at our Frankfurt and Zürich offices) |
| Languages | First call in English; project calls by video in English |
| Time zone | Central European Time (CET/CEST); project teams are led from our international offices |
| Typical timeline | Discovery 1–3 weeks · design 2–5 weeks · first version 8–16 weeks · testing and store release 1–3 weeks (ranges, not guarantees) |
| Pricing | Custom quote after a short brief: fixed-scope project or ongoing product team. No price list. |
| Booking | Free 30-minute video call ↗ |
| Company-wide | 10 offices in 10 markets · 250+ brands · 500+ projects · 4.9+ on Clutch · 8 working languages |
Mobile app development for Paris companies
Paris is France's economic capital and one of Europe's largest start-up scenes, alongside luxury, retail, tourism and the corporate offices of La Défense. French-speaking users expect a fully French app experience.
Paris at a glance
- IndustriesLuxury, fashion and retail, tourism, SaaS, finance, media
- Data lawGDPR and the Loi Informatique et Libertés, supervised by the CNIL
- PaymentsCartes Bancaires (CB) cards, Apple Pay, Google Pay, PayPal
- LanguagesFrench and English
- Time zoneCET in winter, CEST in summer
Luxury, fashion and retail
Shopping, clienteling and loyalty apps with a premium feel.
Start-ups and scale-ups
MVPs and first versions to test an idea with real users.
Large companies and B2B
Field, portal and internal apps for teams across sites.
What our Paris app developers build
Développement d'application mobile, in plain English: iOS and Android apps, Flutter and React Native apps, web apps and the backend behind them.
iOS and Android apps
Swift and Kotlin, full device access.
Cross-platform apps
One React Native or Flutter codebase.
Web apps and PWAs
Portals and tools, no store needed.
Backend, APIs and integrations
Accounts, payments, CRM, ERP.
MVPs and first versions
Test your idea with real users.
Takeover and support
Review, fixes, upgrades, rebuilds.
Native, cross-platform or web app?
Native iOS app development in Swift, Android in Kotlin, or one Flutter or React Native codebase. We recommend one in discovery.
| Native | Cross-platform | Web app / PWA | |
|---|---|---|---|
| Code | Swift (iOS) and Kotlin (Android) | One codebase: Flutter or React Native | One codebase: TypeScript, React |
| Performance and device features | Best; full device access | Very good for most apps | Good; limited device access |
| Time to both stores | Longest: two apps | Usually faster | No store needed |
| Best for | Demanding, device-heavy apps | Most business and consumer apps | Portals and internal tools |
Apps we can build
Common app types; illustrative screens, not client work.
Booking and scheduling
Pick a slot, pay, get reminders.
Shop and loyalty app
Browse, buy, collect points.
Customer portal
Orders and documents, one login.
Field-service tool
Jobs and checklists on site.
Marketplace
Two sides meet and book.
Finance dashboard
Balances and reports at a glance.
- Chat assistant
- Smart search
- Document reading
- Recommendations
How we work
From brief to store release, with a working build at every stage.
- 1BriefScope and quote
- 2PrototypeClickable design
- 3SprintsDemo every two weeks
- 4Store releaseApp Store · Google Play
Timeline
| Phase | Typical duration | You get |
|---|---|---|
| Discovery and scope | 1 to 3 weeks | Written scope and quote |
| UX and UI design | 2 to 5 weeks | Clickable prototype |
| Build in sprints | 8 to 16 weeks for a first version | Test build every sprint |
| Testing and store release | 1 to 3 weeks | Real-device and security testing, store submission |
| Support and next versions | Ongoing, as agreed | Monitoring, updates, next versions |
Typical ranges in weeks, not a guarantee.
How to choose a mobile app agency in Paris
Six checks before you sign, whoever you hire.
Platform fit
Ask which approach they recommend (native, Flutter, React Native or web) and why.
UnFoldMart: We recommend one in discovery.
A written scope and quote
What is in, what is out, and how changes are priced.
UnFoldMart: Scope, timeline and price in writing.
A visible process
A clickable prototype first, then demos and test builds you can install.
UnFoldMart: A demo after every two-week sprint.
Security and data protection
How data is protected and tested before release.
UnFoldMart: OWASP MASVS, security testing before launch.
Store release and ownership
Who submits to the App Store and Google Play, and who holds the accounts and code.
UnFoldMart: App Store and Google Play submission is part of our release step.
Support after launch
Updates for new iOS and Android versions, monitoring and a clean handover option.
UnFoldMart: Support agreed in your quote.
Agency, freelancer or in-house team?
| App agency | Freelancer | In-house team | |
|---|---|---|---|
| Skills | Design, build, testing and release in one team | Usually one specialism | The roles you hire |
| Start | After scope and quote | Often quick | After hiring |
| Continuity | Team covers absences and handover | Depends on one person | High while the team stays |
| Your management effort | Low to medium | Medium to high | High |
| Cost model | Project quote or monthly team | Hourly or daily rate | Salaries, hiring and tools |
| Best for | A full app, start to finish | A defined, smaller task | A long-term core product |
What affects the cost
No price list. Your quote depends on these factors.
- PlatformsiOS, Android, web.
- Screens and featuresHow many, how complex.
- IntegrationsPayments, CRM, ERP.
- Design depthStandard or custom.
- TimelineYour launch date.
- Premium designLuxury and retail brands often need custom visual design and motion.
Ways to work with us
Fixed-scope project
Scope and price in writing.
Ongoing product team
A dedicated team, monthly.
Discovery first
A scope you can use anywhere.
How quoting works
- Short briefWhat and for whom.
- Free 30-minute callBy video, in English.
- Written estimateScope, timeline, price.
- You decideNo obligation.
GDPR, the CNIL and accessibility
This is general information, not legal advice. Your legal adviser has the final word.
GDPR and the Loi Informatique et Libertés
The GDPR sets the rules for personal data across the EU; France's Loi Informatique et Libertés (law no. 78-17) adds the national rules. We plan consent, data minimisation and deletion into the app from the first sprint.
Official source: Loi Informatique et Libertés (Légifrance) ↗CNIL
The CNIL is the French data protection authority. It publishes guidance for organisations, including on cookies and similar trackers in websites and apps.
Official source: cnil.fr ↗European Accessibility Act
EU countries apply the European Accessibility Act through national law from 28 June 2025. It sets accessibility requirements for many consumer services, such as e-commerce and consumer banking, including their apps. We design and test against WCAG 2.2.
Official source: Directive (EU) 2019/882 (EUR-Lex) ↗Public standards we align our work to
Working with us from Paris
One dedicated team; projects are led by UnFoldMart from our international offices.
Our Paris office
75 Avenue de la Grande Armée, 75016 Paris
By video
Workshops, demos and weekly check-ins by video.
Language
Calls and project work in English.
Time zone: Central European Time (CET/CEST)
Office-hours overlap: –
09:00–18:00 local time in both offices. Same time zone as our Amsterdam, Frankfurt, Zürich, Madrid and Warsaw offices.
Company-wide figures across all our services, not app projects.
- Zürich · in person
- Frankfurt · in person
- London
- Amsterdam
- Paris
- Madrid
- Warsaw
- Singapore
- Vancouver
- Gurugram
Frequently asked questions
App development in Paris: before you book a call.
Do you have an office in Paris?
Yes. UnFoldMart's Paris office is at 75 Avenue de la Grande Armée, 75016 Paris. Workshops, design reviews and weekly check-ins with Paris clients take place by video, in English.
How much does it cost to build an app in Paris?
Pricing is custom. Cost depends on platforms, screens and features, integrations, design depth, compliance needs and your timeline. After a short brief and a free 30-minute call, you get a written estimate.
How long does it take to build an app?
Typically: discovery 1 to 3 weeks, design 2 to 5 weeks, build 8 to 16 weeks for a first version, testing and store release 1 to 3 weeks. These are ranges, not guarantees.
Should we build a native app or use Flutter or React Native?
Native (Swift for iOS, Kotlin for Android) suits top performance and deep device features. Cross-platform (Flutter or React Native) shares one codebase and usually reaches both stores faster. We recommend one in discovery.
Can the app be in French and English?
Yes. We set up the app for both languages from the start, so adding or changing text later is a content task, not a rebuild. French is one of our eight working languages.
How do you handle the GDPR and CNIL guidance?
We plan consent, data minimisation and deletion into the app from the first sprint, follow CNIL guidance on cookies and trackers, and collect only the data the app needs. Your legal adviser has the final word.
Can you connect the payment methods French customers use?
Yes. In France most card payments run on the Cartes Bancaires (CB) network, and Apple Pay, Google Pay and PayPal are common too. We connect the methods your payment provider supports.
Do you design apps for luxury and retail brands in Paris?
Yes. We design shopping, clienteling and loyalty apps with custom visual design and motion, tested on real devices, and the brand team reviews every screen in the clickable prototype before we build.
Can you take over an existing app?
Yes. We start with a review of the code, the store listings and the backend, then fix, upgrade or rebuild in steps, so your app stays available.
Can you add AI features to our app?
Yes, for example a chat assistant, smart search, document reading or recommendations, built in with your data under control. See our AI agent development service for more.
Building an app in Paris?
Tell us what you want to build; the quote follows in writing.