App Development Services UK — iOS, Android, Cross-Platform & SaaS

Most mobile apps we ship fall into one of three brackets. A focused MVP — single platform, core flows, no heavy backend — typically takes 8–12 weeks. A full production app with a custom backend, multiple integrations, and both iOS and Android typically takes 4–6 months. A complete SaaS platform with multi-tenancy and subscription billing typically takes 6–9 months. Timeline depends heavily on scope clarity, integration count, and how ready you are to make product decisions — we are explicit about which factors will move the line during scoping.

Both is the default unless your audience is genuinely concentrated on one platform. React Native covers both with a single codebase, properly platform-respecting UX, and 90%+ code reuse — and the performance gap to fully-native is small enough to be invisible to users for the vast majority of products. Native iOS or Android becomes the right call when the app needs deep platform integration (advanced ARKit, complex Bluetooth peripherals, specific gaming engines) or when the team has strong existing expertise in one stack. We give you the recommendation that fits the product, not the one that maximises billable hours.

App pricing scales with scope. Simple MVPs and Progressive Web Apps start around £1,000–£5,000 for tightly scoped builds. Full production mobile apps with custom backends and integrations typically fall in the £15,000–£60,000 range. Multi-tenant SaaS platforms with billing, dashboards, and team management typically start around £25,000 and scale from there. We produce a written scope and fixed quote against the agreed deliverables — there are no surprise change orders for work that was always part of the scope.

Yes — end to end. Provisioning profiles, signing certificates, privacy manifests, data safety declarations, screenshots and store listing copy, TestFlight and Play Console internal testing, and the submission itself. We configure over-the-air updates (Expo Updates or CodePush) so future small releases don't require a full store review for every change.

Yes. We frequently extend or integrate with existing systems — REST or GraphQL APIs over your stack, Stripe and Stripe Connect for payments, HubSpot or Salesforce CRM sync, Firebase for push notifications and analytics, Twilio for SMS, OneSignal or Pusher for real-time, and any bespoke integrations your business runs. Every integration we build includes idempotency, retry logic, webhook signature verification, and observability — so silent failures become impossible.

Yes. SaaS-specific work includes multi-tenant architecture (separate-schema, shared-schema with row-level security, or fully isolated databases for enterprise customers), Stripe or Paddle subscription billing with proper trial, dunning, upgrade, downgrade, and cancellation flows, role-based access for teams and organisations, SSO with Google, Microsoft, and SAML, audit logging that satisfies SOC 2 questionnaires, and admin tooling your support team needs from day one.

Authentication is built around your audience and platform. OAuth 2.0 and JWT with refresh-token rotation for API consumers, session-based auth where it suits, SSO with Google/Microsoft/SAML for enterprise tiers, and secure-enclave key storage with biometric unlock for mobile-specific flows. We follow OWASP Mobile guidance for storage, transit, and code-level security — not as a tick-box exercise but as the baseline real products need.

For specific products, yes. PWAs deliver installable, offline-capable, push-notification-enabled experiences over the web — with URL discoverability, SEO indexability, no App Store review cycle, and no 15-30% platform tax. They are the right call when web reach matters more than App Store discovery and when you don't need deep native integrations. They are not the right call when App Store discovery, complex camera or peripheral integration, or platform-specific monetisation is essential. We are honest about which side your product sits on.

Yes. Real-time features are built on WebSocket, Server-Sent Events, or managed services like Pusher, Ably, or Supabase Realtime depending on the workload. We design the real-time architecture around actual update patterns — broadcast updates differ from per-user channels, and high-frequency telemetry differs from human chat. The choice of transport, fan-out, and presence handling is made during scoping rather than left to default.

Where it matters, yes. Offline-first architecture — local caching, queued mutations, conflict resolution on reconnect, and clear UI for offline states — is built into the app from the start when the use case justifies it. For products with mostly-online workflows, we still cache critical content so the app degrades gracefully on slow networks rather than failing entirely.

Yes — and we strongly recommend it. Apps degrade silently if left alone: dependencies accumulate vulnerabilities, OS updates ship breaking changes annually, store policies tighten without notice, and the analytics nobody is watching show where users are dropping off. Our maintenance retainers cover dependency and security patching, OS compatibility testing on every major release, crash and performance monitoring with engineer triage, store policy compliance updates, and a backlog of small improvements informed by real usage data.

Yes. Whether the existing app is structurally sound but visually dated, performant but missing key features, or fundamentally broken in ways that justify a rebuild, we audit honestly and recommend the path that gives you the best outcome for the budget. For partial rebuilds, we typically refactor in place using a strangler-fig approach rather than throwing away what works.

React Native with TypeScript is our default for cross-platform mobile work, with native Swift or Kotlin modules added where they genuinely matter. Backends typically run on Node.js with TypeScript, with PostgreSQL or MongoDB databases. Cloud infrastructure on AWS, Azure, Google Cloud, or DigitalOcean depending on workload fit. State management with React Query or Zustand, navigation with React Navigation, and CI/CD via GitHub Actions or EAS Build. We pick technology by what your application actually needs — not by which framework is fashionable this quarter.

Yes. Early-stage projects benefit from a different engagement model than mature ones — focused MVPs that ship faster, architecture decisions that let you scale later without rewrites, and pragmatic stack choices that match runway. We help startups understand which engineering decisions matter at MVP stage and which can wait — and we tell you when you don't need the feature you think you need.

Yes. Internal business apps and enterprise platforms typically need stronger authentication and audit controls, SSO and directory integration, role-based access for complex permission models, and integration with existing ERP, CRM, or HR systems. The user interface still matters — internal users abandon bad tools faster than external users do — and we design for it accordingly.