🇬🇧 Mobile App Development · United Kingdom
Mobile apps your users keep coming back to
From MVP to enterprise, we design and build iOS and Android apps with the same obsession we bring to marketing: user acquisition, retention and measurable ROI — not just shipping code.
In short
iGrowix builds native and cross-platform (React Native / Flutter) mobile apps for iOS and Android for clients in the UK. Projects include product strategy, UX/UI design, development, App Store optimisation and post-launch support, with MVPs from £1,749.
What's included
Product strategy & MVP scoping
We define the smallest version that proves your business case, so you validate before you over-invest.
Cross-platform development
React Native and Flutter builds that ship to iOS and Android from one codebase — faster and 30–40% more cost-effective than dual native builds.
UX/UI design
Research-driven app design with prototypes tested on real users before development begins.
Launch & growth
App Store optimisation, analytics, push notification strategy and paid user acquisition from the team that does it for a living.
The work, made visible
What a healthy app launch looks like
An app succeeds twice: once in the store listing that converts browsers to installs, and again in the retention curve that proves people keep using it.
YourApp
★★★★★ 4.8 · 2,140 ratings
Downloads
48K
▲ 212%
Day-30 retention
41%
▲ 2.3×
Crash-free users
99.8%
▲ 0.6%
Daily active users — last 6 months
Firebase — User engagement
Last 12 monthsDAU
9.2K
▲ 3.1×
Sessions / user
5.8/wk
▲ 74%
Uninstalls
2.1%
▼ 61%
Daily active users — 6 months post-launch
Illustrative examples showing typical campaign patterns — not a specific client account. We'll share real, anonymised case data on a discovery call.
Our process
01
Discovery & scoping
Workshops to define users, features and success metrics; fixed-price MVP scope.
02
Design & prototype
Clickable prototype validated with real users.
03
Build & test
Agile sprints with fortnightly demos; automated and device testing.
04
Launch & iterate
Store submission, ASO, analytics and a post-launch growth roadmap.
From idea to MVP: proving the business case before over-investing
The graveyard of failed apps is full of products that built everything before proving anything. Our discovery process exists to prevent that. In structured workshops we define who the app is for, the single job it must do brilliantly, and the smallest feature set that tests whether users agree — the Minimum Viable Product. Everything else goes on the roadmap for after real users have voted with their behaviour.
This discipline is financial, not just philosophical. An MVP scoped this way ships in 10–16 weeks from £1,749, generating real usage data while a fully-featured build would still be in development. Founders raise on that traction; established businesses in the UK validate demand before committing serious budget. Either way, version two is designed from evidence instead of assumptions — which is where most of the value of shipping early actually lives.
Native or cross-platform? An honest engineering answer
For most business applications, cross-platform frameworks — React Native and Flutter — are the rational choice: one codebase shipping to both iOS and Android, 30–40% lower build cost, faster iteration, and performance that's indistinguishable from native for the vast majority of use cases. Instagram, Shopify and Alibaba ship cross-platform code to hundreds of millions of users; the technology stopped being a compromise years ago.
We recommend fully native development in the specific cases that justify it: graphically intensive games, AR experiences, or apps needing deep hardware integration. And a genuine alternative we'll raise when it fits: sometimes you don't need an app at all — a progressive web app can deliver the experience without app-store friction at a fraction of the cost. We'd rather lose a bigger project than build you the wrong thing; that honesty is cheaper for everyone over a five-year relationship.
Design and build: prototypes before code, demos every fortnight
App users are merciless — the average app loses most of its users within days of install, and confusing onboarding is the killer. So we design against real behaviour before development starts: research-driven UX flows, high-fidelity designs, and a clickable prototype tested with people who match your actual audience. Changing a flow in a prototype costs an afternoon; changing it after development costs weeks. The prototype phase pays for itself every single project.
Development runs in two-week agile sprints with a working demo at the end of each — you watch the product grow and steer priorities as you learn, rather than discovering surprises at handover. Quality assurance runs continuously: automated test suites, manual testing on real devices across screen sizes and OS versions, and performance profiling so the app stays fast on the mid-range Android phones half your audience actually owns.
Launch, ASO and the growth most dev shops ignore
Shipping to the stores is a project in itself: App Store and Play Store assets, review-guideline compliance (Apple rejects a meaningful share of first submissions — we handle resubmissions), privacy declarations, and staged rollouts that catch issues while they're cheap. We manage the whole submission pipeline, and set up the analytics, crash reporting and push-notification infrastructure the app needs from day one.
Then comes the part most development shops leave you alone with: getting users. App Store Optimisation — keyword-tuned titles, conversion-tested screenshots, review velocity — is SEO for the stores, and we run it with the same discipline. Beyond ASO, we're a marketing agency: paid user-acquisition campaigns, onboarding funnels tuned to activate users fast, and push and retention strategies that keep them. An app with no acquisition plan is an expensive icon; ours launch with the growth engine attached.
After launch: support, iteration and total cost of ownership
Apps are living products. Operating systems update annually, devices change, and user expectations rise — an unmaintained app degrades from five stars to unusable within a couple of years. Every build includes a warranty period, and most clients continue on a monthly retainer covering OS-compatibility updates, monitoring, security patches and a steady cadence of improvements driven by usage analytics.
We're transparent about total cost of ownership from the first conversation: sensible annual maintenance typically runs 15–20% of the build cost, and the roadmap beyond MVP is costed in phases so finance teams can plan. What you get in return is compounding: each release informed by real behaviour data, retention improving quarter on quarter, and a product that appreciates instead of rotting. The cheapest app is the one built right, once, and maintained — not the one rebuilt from scratch every three years.
Why build your app with a marketing agency, not just a dev shop
The uncomfortable truth of the app economy: distribution fails more products than engineering does. Thousands of well-built apps launch every month into silence, because the team that built them had no plan — and no skills — for acquiring users. A pure development shop hands you a repository and wishes you luck; the store listing, the launch campaign, the onboarding funnel and the retention strategy are 'not their department'. Those are precisely the things that determine whether your investment returns anything.
Because iGrowix is a growth agency first, your app is built by people who think about acquisition from the first wireframe. Onboarding flows are designed against activation metrics, not aesthetics. Analytics events are mapped to the funnel questions you'll actually ask. App Store listings are keyword-researched like the SEO campaigns they are, launch campaigns are planned alongside development rather than bolted on after, and the paid user-acquisition engine is ready the day Apple approves the build. For clients in the UK, that has meant apps reaching their first thousand users in weeks rather than quarters — and a single accountable partner when the numbers need explaining, instead of a dev shop and a marketing agency pointing at each other.
App Development FAQs — United Kingdom
How much does app development cost in the UK?
Domestic app agencies in the UK typically quote several times more for equivalent scope. iGrowix MVPs start from £1,749 using cross-platform frameworks to control cost without sacrificing quality.
Should I build a native or cross-platform app?
For most businesses, cross-platform (React Native or Flutter) is the right choice: one codebase, both stores, 30–40% lower cost. We recommend native only for intensive graphics, AR or deep hardware integration.
How long does it take to build an app?
A well-scoped MVP takes 10–16 weeks from kickoff to App Store submission. Complex apps with backend systems, integrations or marketplaces typically take 4–8 months.
Do you provide support after launch?
Yes — all builds include a warranty period, and most clients continue on a monthly support and iteration retainer covering OS updates, new features and growth marketing.
Ready to talk app development?
Get a free, no-obligation strategy call and a clear plan for your next 12 months of growth — wherever in the world you are.