MOBILE APP DEVELOPMENT.

iOS and Android apps in React Native, Flutter, Swift and Kotlin — with hardened APIs, secure on-device storage, and a penetration test before store submission. A mobile app development company for startups and enterprises in France and the United States.

► Get an App Estimate Cost & FAQ
Overview

Apps that pass the App Store review — and the security review.

Evosec Consulting designs and builds iOS and Android mobile applications for fintech, health, marketplace, logistics and consumer brands. Most of our mobile clients come to us for one of two reasons: they need a senior team that can ship an MVP fast, or they have an existing app that failed a security audit and need people who can both fix it and prove it's fixed.

We are one of the few mobile app development companies with an in-house offensive security team. Before any build goes to TestFlight or Play Console, our pentesters attack it the way a real adversary would — insecure storage, API authorisation, certificate pinning, reverse-engineering resistance — and the developers fix what they find.

What We Build
▌ 01

React Native Apps →

One TypeScript codebase for iOS and Android, sharing logic with your Next.js web app. Our default for startups that need to move fast without doubling their engineering surface.

REACT NATIVE DEVELOPMENT COMPANY · DÉVELOPPEUR REACT NATIVE
▌ 02

Flutter Apps →

Pixel-identical custom UI, heavy animation and 60fps performance across platforms. Ideal for consumer brands where design fidelity is the product.

FLUTTER APP DEVELOPMENT · CROSS-PLATFORM APP DEVELOPMENT
▌ 03

Native iOS & Android →

Swift and Kotlin when the product depends on the platform: HealthKit, CarPlay, background Bluetooth, NFC payments, AR, or the highest security assurance.

IOS APP DEVELOPMENT COMPANY · ANDROID APP DEVELOPMENT COMPANY
▌ 04

Mobile Backends & APIs →

Laravel or Node.js backends purpose-built for mobile: token auth with refresh rotation, push notifications, offline sync, rate limiting and abuse protection. See web development.

MOBILE BACKEND DEVELOPMENT · API DEVELOPMENT
▌ 05

Mobile App Pentesting →

Already have an app? Our security team tests it against OWASP MASVS / Mobile Top 10 and delivers a prioritised report — with the option of our developers fixing the findings.

MOBILE APP PENETRATION TESTING · AUDIT SÉCURITÉ APPLICATION MOBILE
▌ 06

App Store Launch & Growth →

Certificates, listings, privacy labels, Data Safety forms, review responses, phased rollouts, crash monitoring and post-launch maintenance under SLA.

APP STORE SUBMISSION · APP MAINTENANCE · ASO
React Native vs Flutter vs Native
Choose…WhenTypical MVP
React NativeYour team knows React/TypeScript · you share code with a web app · you need to iterate weekly8–12 weeks
FlutterCustom, animation-heavy UI must be identical on both platforms · design-led consumer product8–12 weeks
Native Swift / KotlinDeep platform integration (Health, CarPlay, BLE, NFC) · maximum performance and security assurance12–16 weeks
Secure by Design
  • Keychain / Keystore storage, never plaintext
  • Certificate pinning & TLS hardening
  • Biometric auth & secure session handling
  • Obfuscation & reverse-engineering resistance
  • API authorisation tested for IDOR / BOLA
  • OWASP MASVS pentest before store submission
  • RGPD / GDPR consent & CCPA data handling
  • HIPAA-aware architecture for health apps (US)
Stack
x-platReact Native · Expox-platFlutteriosSwift · SwiftUIandroidKotlin · ComposebackendLaravel · Node.jsinfraAWS · FirebaseciEAS · Fastlane · GitHub ActionssecMobSF · Frida · Burp
FAQ
How much does it cost to develop a mobile app?

A cross-platform MVP (iOS + Android from one codebase) typically costs $25,000–$60,000 (≈ 23k–55k €) and ships in 8–14 weeks. Apps with native modules, offline sync, payments, KYC or medical-grade data handling range from $60,000 to $200,000+. Every project is fixed-price per milestone and includes a mobile penetration test before store submission.

React Native or Flutter?

React Native when your team already knows React/TypeScript or you share code with a web app; Flutter for pixel-identical custom UI and heavy animation. Native Swift/Kotlin when the product depends on deep platform features.

Do you handle App Store and Google Play submission?

Yes — certificates, provisioning, listings, privacy labels, Data Safety forms, review responses and phased rollouts. RGPD consent flows for French clients; CCPA and HIPAA considerations for US clients.

What makes your apps more secure?

Our in-house pentesters test every build against the OWASP Mobile Top 10 before release, and the developers who wrote the code fix the findings. No hand-off, no second vendor.

Do you work with companies in France and the US?

Yes. Nearshore partner for French startups and SMEs (Paris time, French-speaking, RGPD-first); senior remote team for US companies with a daily East Coast overlap window. EUR or USD invoicing.

► Start a Mobile Project Pentest an Existing App →