Web app development UK — senior-built, shipped fast.
I build custom web apps and mobile apps for founders, service businesses, and teams that need something bespoke and need it working. Senior engineering on every project, fixed scope before build starts, and a timeline measured in weeks. theogpt.ai is an AI chat tool I built myself. Zero to launched in 18 days. From £8,000.
From £8,000
Web app builds run 6–10 weeks for focused scope. Adding mobile (iOS + Android) typically adds 4–6 weeks. Scoped individually before build starts.
When you'd hire me for this
- You have an idea for a product or internal tool and need an experienced engineer to build the first working version
- You need a senior engineer who will scope the work honestly and build it — not a team you'll never meet quoting a number that grows on contact
- You need a mobile app alongside a web backend — iOS and Android, same codebase
- You're a small team that needs a custom internal tool and doesn't want to pay ongoing SaaS fees for something you could own outright
- You have a working prototype and need it rebuilt properly before taking it to market or investors
What you get
- A working, deployable application. Not a prototype, not a demo, not "Phase 1 of 6".
- A scope document before build starts: what's in, what's out, what it costs, when it ships
- Senior architecture decisions throughout. Every call I make is one that will matter in two years.
- Full documentation and a working partnership from launch onward. If you ever bring in another developer, everything they need is already in place.
- First month of post-launch partnership included
- Full code ownership from day one. No lock-in, no ongoing dependency on me.
How I work
Brief
The first call is a brief, not a pitch. Tell me what the app needs to do and who it's for. I'll ask questions about complexity, integrations, and what "done" looks like.
Scope
Scoping takes a few days. I map the feature set, data model, and any third-party integrations. You get a written scope doc with a fixed price and timeline before anything is built. Clear numbers before build starts — not after.
Build
Build is iterative. I share a working version after the first two weeks. Real software, not Figma screens. Weekly check-ins. Feedback incorporated in the next week's build, not in a batch at the end.
Mobile (if in scope)
For mobile apps, I build for iOS and Android from a single codebase. No need to pay for two separate development tracks. The web backend and mobile app are architected together.
Launch
Typical timelines: a focused web app development project runs six to ten weeks. Adding a mobile app alongside typically adds four to six weeks. More complex apps with multiple integrations, custom backends, or data-heavy features will be scoped accordingly.
What it costs
Most web app projects land between £8,000 and £20,000. Apps that include a mobile component (iOS + Android) or significant backend complexity (custom APIs, third-party integrations, data pipelines) typically run £15,000 to £35,000.
Where a project lands in those bands depends on three things: feature scope, integration complexity, and whether mobile is included. Every project is scoped individually and priced before build starts.
Every project scoped individually. Bands are honest guides, not menu prices.
FAQ
Tell me about your app
15-minute free call. Tell me what the app needs to do. I'll tell you what's realistic, what it'll take, and whether I'm the right person for it. Written proposal within three working days.