Mobile Apps Built to Ship, Perform and Scale.
Native and cross-platform mobile app development for iOS and Android. From MVP to full-featured product. We design, build and deploy mobile applications that work reliably and grow with your business.
What is Mobile App Development?
Mobile app development is the process of designing, building and deploying software applications for iOS and Android devices, using either native languages (Swift for iOS, Kotlin for Android) or cross-platform frameworks such as React Native or Flutter that compile to both platforms from a shared codebase. A complete mobile development engagement covers UX design, frontend and backend engineering, third-party API integration, quality assurance across physical devices, and submission to the App Store and Google Play. For B2B companies and product teams, mobile development is the discipline that turns a product concept or an existing web-based workflow into a performant, maintainable mobile application that users adopt and retain.
Signs You Need Mobile App Development
- Your users are asking for a mobile experience and your web app does not perform adequately on phones, leading to churn you can attribute directly to the lack of a native app.
- Your field teams, drivers, technicians or remote staff need to use your platform offline or in low-connectivity environments where a web browser is insufficient.
- You have a consumer or prosumer product where app store distribution, push notifications and home screen presence are essential to your acquisition and retention model.
- Competitors have launched mobile apps and your sales team is losing deals because prospects see the absence of a mobile product as a signal of immaturity.
- You have a validated product idea or an existing web platform that needs a mobile layer to unlock a new user segment or distribution channel.
Who This Is For
B2B SaaS Teams Adding a Mobile Layer
SaaS products built on web that need iOS and Android apps to close enterprise deals, serve mobile-first user segments, or extend platform reach into field use cases.
Startups Building a Mobile-First Product
Founders with validated concepts who need an MVP built fast, correctly and to app store standards, without building a full in-house mobile team before product-market fit.
Operations Teams Needing Field Apps
Logistics operators, facilities managers and field service companies whose staff need purpose-built mobile tools that work offline and integrate with back-office systems.
Product Teams Replacing an Ageing App
Companies with a legacy mobile app that is slow, poorly rated or built on an unmaintainable codebase, who need a clean rebuild with modern architecture and full ownership.
What You Get
- iOS App (Swift or React Native)Production-ready iOS application tested on physical devices and submitted through App Store Connect with all required metadata.
- Android App (Kotlin or React Native)Production-ready Android application tested across device classes and submitted to Google Play Console with store listing and content ratings.
- UX Wireframes and UI Design SystemFull wireframe set, component library and interactive prototype delivered and approved before development begins.
- API Integration and Backend ConnectivityAll third-party services, internal APIs, payment gateways and CRM systems connected with authenticated, documented endpoints.
- Push Notification SystemFirebase or platform-native push notification setup with segmentation, scheduling and deep-link routing from notification to in-app destination.
- Analytics and Crash ReportingFirebase Analytics or equivalent integrated for user behaviour tracking, with Sentry or Crashlytics for error monitoring from launch day.
- App Store Submission and ListingApp Store and Google Play listings with screenshots, keyword-optimised descriptions, privacy policy linkage and content rating submissions handled in full.
- Post-Launch Support WindowMonitored support period after launch for bug fixes, OS compatibility issues and user-reported problems before handover or retainer transition.
What Mobile Development Covers
iOS App Development
Native Swift development for iPhone and iPad. Optimised for Apple Human Interface Guidelines, App Store review and iOS-specific features including push notifications, Face ID and background processing.
Android App Development
Native Kotlin development for Android devices. Full Material Design compliance, Google Play submission and integration with Android-specific APIs, widgets and background services.
Cross-Platform (React Native)
Build once, deploy to both iOS and Android with 80% code sharing and near-native performance. The right choice for most MVPs and B2B applications where speed and cost efficiency matter.
API Integration & Backend
Connecting your mobile app to existing APIs, CRM systems, payment gateways and third-party services so the app functions as part of your wider product ecosystem, not as an isolated silo.
The Koldconvert Mobile Product System
Most offshore mobile shops treat an app as an isolated artefact: they build what is in the spec, submit to the stores, and hand over the repo. The Koldconvert Mobile Product System treats mobile development as a product discipline embedded in a business context. Before writing code, we map how the app fits the user's daily workflow, how it connects to your existing systems, and how performance will be measured after launch. Development runs in 2-week sprints with working builds delivered for testing throughout, not a 12-week blackout followed by a reveal. Post-launch, we monitor crash rates, session data and store reviews in the first 30 days and act on what we find. The result is an app that ships on time, works reliably and improves measurably after it goes live.
How We Build Your Mobile App
Design
UX wireframes, UI design and interactive prototype before a single line of code is written. Every screen reviewed and signed off by stakeholders.
Build
Agile development in 2-week sprints using React Native, Swift or Kotlin. Regular builds delivered to your team for testing and feedback throughout the cycle.
Test
Device testing across physical iOS and Android hardware, performance testing under real-world load conditions, and app store compliance review against current guidelines.
Launch
App Store and Google Play submission with full metadata, screenshots and listing copy. Post-launch monitoring and first-round user feedback fix cycle included.
Tools & Technology
React Native and Expo handle cross-platform builds with a single JavaScript codebase. Swift and Kotlin are used where platform-native performance is required. Firebase and Supabase provide auth, real-time database and push notifications in the backend layer. Stripe handles payment flows. Fastlane automates build, signing and deployment to both stores, and App Store Connect and Google Play Console are where releases are managed and monitored.
How We Work Together
Fixed-Scope MVP Build
A defined scope, fixed price and fixed timeline engagement to ship an MVP to both app stores. Suited to founders and product teams with a clear feature set. Deliverable: live app on iOS and Android. Typical duration: 8 to 12 weeks.
Full Product Build
End-to-end design and development for a full-featured mobile product with complex integrations, custom UX and backend architecture. Suited to Series A stage companies or established businesses extending an existing product. Typical duration: 16 to 24 weeks.
Ongoing Development Retainer
Monthly retainer providing dedicated mobile engineering capacity for feature development, OS compatibility updates, performance improvements and incident response. Suited to live products with an active feature roadmap.
What Clients Achieve
Mobile App Results
Mobile App Development for Your Industry
FinTech & Payments
PSD2-compliant payment flows, biometric authentication, real-time balance and transaction views. Stripe and open banking API integration with secure token storage following OWASP mobile guidelines.
HealthTech & MedTech
HIPAA-aware architecture, HealthKit and Google Fit integration, appointment and teleconsultation flows, and offline-capable patient data access for clinical environments with unreliable connectivity.
E-commerce & Retail
Native mobile shopping experiences with deep-link product pages, Apple Pay and Google Pay checkout, personalised push campaigns and barcode scanning for in-store inventory lookups.
SaaS & B2B Software
Mobile companions to existing web platforms, enabling account managers, executives and field teams to access CRM data, dashboards and approval workflows from any device.
Logistics & Supply Chain
Driver and warehouse apps with barcode and QR scanning, GPS tracking, offline job queues that sync on reconnection, and proof-of-delivery signature capture.
EdTech
Learning apps with offline content downloads, progress synchronisation, video streaming, push reminders for course completion, and parent and student account management.
Media & Entertainment
Content streaming apps, subscription paywall implementation via StoreKit and Google Billing, social sharing flows, and low-latency video player architecture optimised for mobile networks.
Real Estate Tech
Property search with map-based browsing, virtual viewing integrations, mortgage calculator tools and instant notification on new listings matching saved searches.
HR Technology
Employee apps for shift scheduling, time and attendance tracking, leave requests, payslip access and internal communications, integrating with existing HRMS and payroll systems.
InsurTech
Policy management, FNOL claims submission with photo capture, telematics integration for usage-based insurance products, and ID verification flows using mobile camera APIs.
Legal Tech
Secure document review, e-signature workflows, matter status notifications and client-facing portals with end-to-end encryption and GDPR-compliant data handling.
Marketplaces & Platforms
Two-sided marketplace apps with separate buyer and seller flows, in-app messaging, listing management, payout tracking and review systems built for engagement and trust.
Koldconvert vs Generic App Development Agencies
| Factor | Koldconvert | Generic App Agency |
|---|---|---|
| Business context | App scoped within your product strategy, growth model and existing tech stack | Builds to spec with no view of how the app fits the wider business |
| Design process | Full UX research, wireframes and interactive prototype before any code | Templates or thin wireframes handed straight to developers |
| Development transparency | Working builds delivered every 2 weeks for stakeholder review | Long blackout periods followed by a big reveal near deadline |
| Post-launch | 30-day monitored support window; retainer available for ongoing work | Repo handover and exit; bugs billed as new project scope |
| Security | OWASP Mobile Top 10 applied by default on every build | Security review optional or absent unless specifically requested |
| App store strategy | ASO-optimised listing copy, screenshots and keyword targeting included | Default metadata submitted with minimal optimisation |
| Growth alignment | Analytics, push and in-app events configured for your acquisition and retention model | Analytics installed as an afterthought; no connection to growth strategy |
The mobile app market is oversupplied with agencies that will build you an app and undersupplied with partners who care whether it retains users after month one. Most mobile development failures are not engineering failures: they are scoping failures, where the app was built without real understanding of the user's daily workflow, the integration requirements of the wider tech stack, or the acquisition channel that was supposed to drive downloads. Koldconvert starts every mobile engagement by answering those questions before touching a design tool, because an app that ships but does not get used is a cost, not an asset. The quality bar we apply is the one a senior iOS or Android engineer would apply to their own product, not the minimum required to clear app store review.
Koldconvert Strategy Team
Questions to Ask Any Mobile App Development Partner
- Can I see the last three apps you shipped and speak to those clients? Portfolio links prove design capability. Client references reveal delivery reliability, communication quality and what happened post-launch. Any agency reluctant to provide references is signalling something worth investigating.
- Who exactly will be writing the code, and where are they based? Agencies often sell UK or US presence but offshore delivery. A good answer names the engineers, their experience and their time zone. A weak answer references a distributed team without specifics.
- How do you handle scope changes during development? Every project encounters changes. A good answer describes a transparent change control process with documented impact on cost and timeline. A weak answer says "we'll figure it out" or presents all changes as included.
- What does your testing process look like on physical devices? Simulator-only testing misses real-world issues with battery, memory and network behaviour. A good answer names the device classes tested, the testing framework used and how edge cases are documented and tracked.
- What do you hand over at the end of the project and who owns the code? You should receive the full source code repository, design files, credentials and documentation at project end. If an agency retains ownership or uses proprietary frameworks that create dependency, that is a commercial risk worth pricing into the decision.
Glossary
- React Native
- React Native is an open-source JavaScript framework developed by Meta that allows developers to build iOS and Android apps from a single shared codebase, compiling to native platform components rather than running in a web view, which gives it near-native performance with significantly faster development cycles than maintaining separate native codebases.
- App Store Optimisation (ASO)
- App Store Optimisation is the practice of improving an app's visibility and conversion rate within the Apple App Store and Google Play Store through keyword research, title and subtitle optimisation, screenshot design, rating management and localisation, directly affecting organic download volume without paid advertising spend.
- Offline-First Architecture
- Offline-first architecture is a mobile development pattern where the app is designed to function fully without an active internet connection, storing data locally and queuing actions that are synchronised with the backend when connectivity is restored, essential for field service, logistics and healthcare applications used in areas with unreliable networks.
- Deep Linking
- Deep linking is the practice of routing users from an external source, such as an email, push notification or web URL, directly to a specific screen within a mobile app rather than the app's home screen, which significantly improves campaign conversion rates and reduces drop-off from push notification flows.
- TestFlight / Internal Testing Track
- TestFlight (Apple) and the Internal Testing track (Google Play) are the platform-provided distribution channels for sharing pre-release builds of a mobile app with up to 10,000 testers without going through full app store review, enabling stakeholders and QA teams to test new builds throughout the development sprint cycle.
- Over-the-Air (OTA) Updates
- Over-the-Air updates, available in React Native via Expo Updates or CodePush, allow JavaScript bundle changes to be pushed to users' installed apps instantly without requiring a new app store submission and review cycle, enabling rapid bug fixes and minor feature releases between full version updates.
Common Questions About Mobile App Development
Cross-platform with React Native is right for most B2B applications and MVPs. It delivers near-native performance with one shared codebase across iOS and Android, cutting build time and maintenance cost. Native Swift or Kotlin is recommended when you need deep platform-specific APIs, maximum graphics performance, or app store features unavailable to cross-platform frameworks.
An MVP with core features takes 8 to 12 weeks. A full-featured application with complex integrations and custom design takes 16 to 24 weeks. Timeline depends on feature scope, number of API integrations and design complexity. We scope accurately on the discovery call before any work begins.
Yes. Every project includes UX wireframing, UI design and an interactive prototype before development starts. We can work from your existing brand guidelines or design the visual identity from scratch.
Yes, starting with a codebase audit. We review existing code quality, architecture, dependency health and technical debt before committing to a timeline or scope. This protects both parties from inherited problems being misrepresented as new scope.
Yes. We prepare all metadata, screenshots, listing copy and compliance documentation, submit to both the Apple App Store and Google Play Store, and manage the review and approval process including responding to rejection feedback.
MVP builds typically start from £25,000 to £50,000 depending on complexity and platform requirements. Full-featured applications with design, backend integration and app store submission range from £50,000 to £150,000. We provide a fixed-scope estimate after the discovery call so there are no cost surprises mid-project.
An agency is faster to mobilise for a defined product scope and removes the overhead of hiring, managing and retaining a full mobile team before product-market fit. In-house teams make more sense once you have a live product with an ongoing feature roadmap and enough mobile work to sustain full-time engineers. Most early and mid-stage product teams build with an agency first.
FinTech, HealthTech, SaaS, logistics, e-commerce, EdTech, real estate, HR technology and marketplaces, among others. Each vertical has specific compliance, integration and UX requirements. We scope with those constraints understood from day one, not discovered midway through build.
Yes. Offline-first architecture using local storage, sync queues and conflict resolution is available where field use or low-connectivity environments require it. This is standard for logistics, field service and healthcare applications where network availability cannot be assumed.
We provide a post-launch support window for bug fixes, crash monitoring and OS compatibility issues. Ongoing retainer arrangements are available for feature development, performance improvements and incident response. We do not hand over the repo and disappear.
React Native is our default for cross-platform builds due to its JavaScript ecosystem, large component library and strong community. Flutter is available for projects where the design requires pixel-perfect custom UI that benefits from Flutter's rendering engine, or where the team has existing Dart experience.
Koldconvert positions mobile apps within a wider product and growth context. Development work is informed by conversion thinking, user acquisition strategy and revenue operations, not engineering alone. An app built by Koldconvert is designed to work within your business system and improve measurable metrics after launch, not just pass app store review.
Ready to build your mobile app?
Tell us what you need to build and we will scope it accurately on a single discovery call.