Expert Mobile App Developers in London — iOS, Android & Cross-Platform
Fulminous Software is a team of experienced mobile app developers in London delivering custom iOS, Android, Flutter, and React Native applications for UK startups, SMEs, and enterprises. Transparent GBP pricing. Two-week sprint delivery. 150+ apps shipped.
- Native iOS & Android and Cross-Platform Development
- Flutter, React Native, Swift & Kotlin Specialists
- App Store & Google Play Submission Included
- UK GDPR Compliant — UK Data Residency by Default
- Post-Launch Support & Maintenance Available
Mobile App Developers Tailored for London Businesses
London's business market moves fast. Off-the-shelf apps rarely cut through. What growing businesses actually need is a mobile application built around their specific workflow, customer journey, and commercial goals — not a template stretched to fit.
At Fulminous Software, our London mobile app developers work with you from the very first conversation: understanding your users, your business model, and the problem the app needs to solve. From that starting point, every design decision, technical choice, and sprint goal is driven by outcomes — not process for its own sake.
- End-to-End Delivery: Strategy, UI/UX design, development, testing, App Store submission, and post-launch support — all from one team.
- Scalable Architecture: Apps built to handle growth from day one — not rebuilt six months after launch.
- Agile Sprints: You see working features every two weeks. No disappearing for months and hoping for the best.
- Transparent GBP Pricing: Itemised quotes before any work begins. No hidden costs, no scope creep surprises.
- Framework-Agnostic Advice: We recommend what suits your project — Flutter, React Native, Swift, or Kotlin — not what we happen to prefer building.
Our Mobile App Development Services in London
From native iOS and Android builds to cross-platform Flutter apps and legacy app modernisation — our London mobile app developers cover the full spectrum of mobile development for UK businesses of every size.
iOS App Development London
Native iPhone and iPad apps built in Swift, designed for performance, App Store compliance, and exceptional user experience.
- SwiftUI and UIKit development
- Apple Watch and iPad optimisation
- App Store submission & review management
Android App Development London
Native Android apps built in Kotlin for the full range of Android devices — from consumer phones to enterprise tablets.
- Jetpack Compose and Material You
- Google Play submission & review
- Android Enterprise and MDM support
Flutter App Development London
Single codebase covering iOS, Android, web, and desktop — with pixel-perfect, brand-consistent UI and near-native performance.
- Google's official cross-platform framework
- 30–40% cost saving vs two native builds
- Consistent UI on every device and OS
React Native App Development
JavaScript-powered cross-platform apps — ideal when your team already works with React or when you need to share code with a React web platform.
- Shared codebase with your React web app
- Large library of native modules
- Faster hiring from UK JavaScript talent pool
Enterprise Mobile App Development
Robust enterprise mobile applications — CRM apps, field service tools, ERP extensions, and internal workflow platforms — built for scale and security.
- Role-based access and SSO integration
- Offline-first architecture for field workers
- Salesforce, SAP, and ERP integration
App Modernisation & Redesign
Bring your existing app up to current standards — improved UI/UX, updated architecture, performance optimisation, and compliance with current OS versions.
- Full technical and UX audit before work begins
- Data migration without downtime
- iOS 17+ and Android 14+ compatibility
Our Mobile App Development Process
Every Fulminous mobile app project follows a structured, transparent process — with regular checkpoints so you are always in control of your project and budget.
Discovery & Scoping
Understanding your business goals, users, and technical requirements. We define the scope and produce an itemised GBP quote.
UI/UX Design
Interactive wireframes and high-fidelity prototypes. You sign off every screen before development begins.
Agile Development
Two-week sprints with working demos. You test real features throughout the build — not just at the end.
QA & Testing
Rigorous cross-device testing, performance profiling, and security review before any submission.
App Store Submission
We handle App Store and Google Play submission, including metadata, screenshots, and review responses.
Launch & Monitoring
We monitor performance, crash reports, and user feedback post-launch and address issues rapidly.
Ongoing Support
Post-launch maintenance, OS update testing, feature additions, and 24-hour critical support response.
Growth & Iteration
We analyse app store reviews, analytics, and user behaviour to plan your next feature roadmap.
Mobile App Development Cost in London
All costs below are in GBP and represent typical 2026 ranges for London projects. Every project begins with a free consultation and itemised fixed-price proposal — so you know exactly what you are paying for before we start.
Basic App
Up to 8 screens, user authentication, core functionality, basic API integration, and App Store + Google Play submission.
- iOS and Android (cross-platform)
- User login and profile management
- Basic CMS or admin panel
- Push notifications
- Timeline: 2–4 months
Mid-Level App
Custom UI, multiple integrations, payment processing, real-time features, admin dashboard, and backend API.
- Custom UI/UX design throughout
- Third-party API and CRM integration
- In-app payments and subscriptions
- Real-time data and chat features
- Timeline: 4–8 months
Complex / Enterprise App
Advanced features, AI integration, multiple user roles, enterprise backend, real-time data, and full compliance requirements.
- Multiple user roles and permissions
- AI and machine learning features
- Enterprise system integration
- FCA, GDPR, or NHS compliance
- Timeline: 8–18 months
Not sure which tier fits your project? Talk to us free — no obligation.
Technologies Our London App Developers Use
We choose the right tool for each project — not the one that's easiest for us to build in. Every technology below is in active production use across our current London client projects.
Cross-Platform
- Flutter (Google) — Dart
- React Native (Meta) — JavaScript
- Ionic — Web Technologies
- Xamarin — C# / .NET
Native Mobile
- Swift — iOS / iPadOS
- SwiftUI — Modern iOS UI
- Kotlin — Android
- Jetpack Compose — Android UI
Backend
Cloud Infrastructure
- AWS — EC2, Lambda, S3, RDS
- Microsoft Azure — UK regions
- Google Cloud Platform
- Firebase — Real-time & auth
Databases
- PostgreSQL — Relational data
- MongoDB — Document store
- Firebase Firestore — Real-time
- Redis — Caching & sessions
Integrations
- Stripe & PayPal — Payments
- Salesforce & HubSpot — CRM
- Twilio — SMS & Voice
- Google Maps, Mapbox — Location
Why London Businesses Choose Fulminous Software
There are dozens of mobile app agencies in London. Here is what consistently sets Fulminous apart — in plain terms, not marketing language.
🎯 Framework-Agnostic Advice
We do not have a preferred framework that we push regardless of your project. We recommend Flutter, React Native, Swift, or Kotlin based on what genuinely suits your requirements — and we explain why in plain English.
📅 Two-Week Sprint Delivery
You see a working version of your app every fortnight — not at the end of a six-month build cycle. This keeps projects on track, on budget, and allows you to give real feedback while there is still time to act on it.
💷 Transparent GBP Pricing
Every project starts with an itemised GBP proposal. No vague estimates. No "it depends" without explanation. You know exactly what each feature costs before we write a line of code.
🏆 150+ Apps Delivered
Over seven years we have shipped mobile applications for UK clients in fintech, healthcare, retail, logistics, hospitality, and education. Real portfolio, real clients, verifiable on Clutch and Trustpilot.
🔒 UK GDPR & Compliance Ready
Every app we build includes UK GDPR compliance as standard — UK data residency, consent management, audit logging, and data subject access request support. FCA and NHS DSPT alignment available for regulated sectors.
🤝 Long-Term Partnership
Most of our clients have worked with us for three or more years. We offer post-launch maintenance retainers, 24-hour critical support response, and ongoing feature roadmap planning — not just a handover and goodbye.
Industries Our London App Developers Serve
We build mobile applications for London businesses across a wide range of sectors — each with its own compliance, UX, and integration requirements. Our experience means you are not our test case.
💳 Fintech & Banking
Mobile banking apps, payment wallets, investment platforms, and KYC flows built with FCA awareness and PCI-DSS security.
🏥 Healthcare & NHS
Patient-facing apps, appointment booking, symptom checkers, and clinical tools. UK GDPR, DTAC, and NHS DSPT compliant.
🛒 Retail & eCommerce
Shopping apps, loyalty platforms, inventory tools, and click-and-collect experiences integrated with Shopify, Magento, and WooCommerce. See our retail application development services.
🚚 Logistics & Delivery
Driver apps, route optimisation, real-time tracking, proof of delivery, and fleet management tools for London logistics businesses.
🎓 Education & EdTech
Learning management systems, student portals, assessment apps, and coaching platforms for London schools and EdTech startups.
🍽️ Hospitality & Food
Restaurant ordering apps, table booking platforms, hotel guest experience apps, and loyalty programmes for London hospitality brands. Explore our restaurant application development services.
🏋️ Fitness & Wellness
Workout tracking, coaching apps, nutrition platforms, and wearable integrations for London fitness brands and health startups.
🏗️ Construction & Property
Site management apps, property search platforms, inspection tools, and tenant portals for London's built environment sector.
⚙️ Enterprise & B2B
Field service apps, CRM extensions, internal workflow tools, and reporting dashboards for London enterprises needing mobile-first operations.
Mobile App Development Across London
We deliver mobile app development services to businesses across all 32 London boroughs. Whether you are based in the City, Canary Wharf, Shoreditch, or anywhere across Greater London — you get the same senior development team.
Central London
Finance & tech
Canary Wharf
Banking & fintech
Shoreditch
Tech City startups
Westminster
Government & corporate
Camden
Creative & retail
Hackney
Startups & eCommerce
Southwark
Media & professional
Croydon
Insurance & SME hub
Islington
SaaS & tech
Tower Hamlets
Fintech & logistics
Lambeth
Healthcare & education
Ealing
Retail & hospitality
Flexible Engagement Models for London Businesses
We work the way that suits your project — not a single rigid model. Choose from three proven approaches depending on your budget certainty, project stage, and team structure.
Fixed Price
Best for well-scoped projects with a defined feature set and firm budget. You know exactly what you are paying before we start.
- Full scope defined upfront
- Predictable cost and timeline
- Ideal for MVPs and defined projects
- Milestone-based payment schedule
Time & Material
Best for evolving projects where requirements may change as the product takes shape. You pay only for what is built.
- Flexible scope as you go
- Ideal for product discovery phases
- Weekly or sprint-based billing
- Full visibility of hours and progress
Dedicated Team
Best for ongoing development, long-term product roadmaps, or when you need senior mobile developers to extend your existing team. Hire dedicated software developers on full-time or part-time engagement.
- Dedicated developers, exclusively on your project
- Full-time or part-time engagement
- Scales up or down as needed
- Direct communication with your team
Our Portfolio
Be Active You
Fitness App & Website
The perfect integration of technology and the fitness industry — workout plans, nutrition tracking, and community features in a single polished mobile experience.
View Case Study →
What Our London Clients Say
"Fulminous delivered our retail app on time, within budget, and with exactly the feature set we discussed. The two-week sprint approach meant we were never in the dark. The app went live and we saw a 22% uplift in repeat orders within the first month."
Sarah L. CEO, RetailTech Ltd — London"We came to Fulminous with an existing logistics app that was causing us problems — crashes, slow load times, poor UX. They audited it, gave us a clear rebuild plan, and delivered a dramatically better product within four months. Highly recommended."
James T. Operations Director, London Logistics Co."As a healthcare startup we needed a development partner who understood compliance as well as code. Fulminous asked the right questions from day one — GDPR, data residency, NHS integration — and delivered an app we were confident launching."
Ben McCabe Founder, HealthTech Startup — LondonFrequently Asked Questions
Everything London businesses ask us before starting a mobile app project.
Mobile app development in London typically costs £15,000 to £35,000 for a basic app, £35,000 to £100,000 for a mid-level app with custom features and integrations, and £100,000 to £250,000+ for complex enterprise apps. Costs depend on the number of screens, platform choice, backend complexity, and third-party integrations. Fulminous provides itemised GBP quotes before any work begins.
A basic app takes 2 to 4 months. A mid-level app with custom UI and integrations takes 4 to 8 months. Complex enterprise apps with AI features and multiple user roles take 8 to 18 months. We work in two-week sprints — you see working features throughout the build, not just at the end.
Yes. We build cross-platform apps using Flutter and React Native, covering both iOS and Android from one codebase — reducing cost by 30 to 40% versus separate native builds. For projects needing maximum platform-specific performance, we also build fully native iOS apps in Swift and Android apps in Kotlin.
Absolutely — and it is one of our most requested services. We audit your existing app technically and from a UX perspective, identify what needs rebuilding versus what can be kept, and produce a clear improvement plan with costs. Most modernisation projects take 3 to 6 months depending on the scale of changes required.
Yes — fully. App Store and Google Play submission is included in every project we deliver. This covers app metadata, screenshots, privacy policy requirements, age ratings, and responding to reviewer queries if Apple or Google requests additional information. We manage the process so you do not need to navigate it yourself.
Yes. Every project includes a post-launch support period and we offer ongoing maintenance retainers covering App Store and Google Play updates, OS compatibility testing after major iOS and Android releases, bug fixes, performance monitoring, and feature roadmap planning. We respond to critical issues within 24 hours.
Yes — UK GDPR compliance is built into our architecture from the start. This includes UK data residency on AWS or Azure UK regions, consent management, data minimisation, audit logging, and data subject access request support. For regulated sectors we also support FCA, PCI-DSS, and NHS DTAC compliance requirements.
We have delivered 150+ digital products for UK businesses across seven years. We offer transparent GBP pricing, two-week sprint delivery, framework-agnostic advice, and long-term partnership. Our London office is at 19 Tate Road, E16 2HJ. Verified reviews on Clutch and Trustpilot. Contact us at +44 734 433 5857 or info@fulminoussoftware.com.
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