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Full-stack product studio

Launch your app in weeks, with AI built in

We design, build, and launch mobile apps, web apps, and custom websites, with AI woven in from day one. One team takes you from first idea to a live product.

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See our work

Free 30-minute discovery call. Fixed scope and price agreed up front. No obligation after the call.

  • 11+ Years building
  • 10+ Products shipped
  • 70+ Apps published
  • 3,000,000+ Combined downloads
  • 24h Reply time
Launch
  • You own 100% of the code
  • Fixed scope and price up front
  • Not happy after milestone one? Walk away, owe nothing

The modern stack we build on

  • Flutter
  • React
  • Astro
  • WordPress
  • TypeScript
  • Tailwind CSS
  • Firebase
  • Supabase
  • OpenAI
  • Claude
  • Stripe
  • RevenueCat
  • Resend
  • OneSignal
  • Vercel
  • Cloudflare

Products we have shipped

Why projects stall

Most products never make it to launch

Slow builds, generic UX, and platform friction kill momentum. We remove all three.

Slow development

Traditional builds drag on for months. We ship polished, production-ready products in weeks with Flutter, React, and AI-assisted workflows.

Generic experiences

Template-driven apps feel lifeless. We craft custom interfaces with motion and detail your users actually remember.

Platform friction

Building separately for every device wastes time and budget. One codebase flows across iOS, Android, and web.

How we work

Your vision, unconstrained.

We pair modern engineering with senior design judgment and AI tooling, so your product goes from concept to launch in record time, without cutting corners on quality.

  • Rapid delivery, weeks not months
  • AI features built into the core
  • Production-grade, high-performance builds
Compared with prompting an AI yourself or hiring a cheap developer, working with us means your product is built for your idea, kept hands-off, optimized, expert-tested, and launched with support.
AI alone Cheap route With us
Looks done
Built for your idea
You stay hands-off
Optimized, reliable code
Expert-tested
Launched and supported

AI and cheap shortcuts get you started. A senior expert ships the real thing.

4 wk

Typical MVP timeline

[ NODE_SCALING: 4.0 ]
Capabilities

Everything you need to ship

Cross-Platform App Development

Cross-platform app development: native-quality iOS and Android apps from one Flutter codebase, shipped in weeks at a fixed scope and price.

See what you get

Web App Development

Web app development with React and Astro, from customer dashboards to full SaaS platforms. Built to scale, tuned for speed, at a fixed price.

See what you get

AI Integration Services

OpenAI and Claude built into your product logic to power real, useful features. Practical AI integration that earns its place, not gimmicks.

See what you get

MVP Development for Startups

MVP development in weeks, not quarters, so you can launch, learn, and raise faster. Fixed scope, fixed price, and a clear path to grow.

See what you get

Custom Website Development

Custom website development on Astro or WordPress: high-converting marketing sites tuned for speed, SEO, and turning visitors into customers.

See what you get

Backend Development and Integration

Backend development and API integration: secure auth, solid data, and apps that connect to the business system you already run.

See what you get

UI/UX Design

Product design that feels premium and converts: interface systems, user flows, and visual identity for apps, web apps, and AI products.

See what you get

Internal Business Apps

Custom internal software for your team: operations, scheduling, approvals, dashboards and field apps, fitted to the systems you run.

See what you get

Elephant feeding

Hand-delivered peanuts, served with care. Every elephant fed on time, trunk-friendly guaranteed.

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Selected work

Recent work

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Client voices

Trusted by founders

By far my best freelance experience ever! I will definitely hire him again! Janos did extra steps that he wouldn't have to do, but still did! Our communication was perfect! I could tell that he definitely knew what he is doing! Thanks a lot.

Hussein Al-Rammahi

MizanMe

Jani was the best possible choice for building our project. Cooperative, constructive and quick to understand how the business works, so we could count on Jani not only for the technical build but also for the extra ideas contributed along the way. Always available and flexible, and open to questions, requests for help or a quick catch-up at any time. That attitude and professional mindset made working together much easier. I recommend Jani wholeheartedly.
Read the full review

Antónia Oláh-Kovács

Entrepreneur

Translated from Hungarian

CompletApp transformed our business. We needed an app to launch quickly but did not have the in-house expertise, and they delivered a beautiful, functional app in just weeks.

Sarah T.

Marketing Director, FreshBite Foods

Fast, reliable, and easy to work with. As a startup founder I needed an app to demo to investors, and CompletApp delivered a sleek, responsive design that matched my vision perfectly.

David M.

Founder, FitForce

Exceeded all our expectations. We struggled for months to find the right team to bring our app idea to life, and CompletApp made it happen.

Emily J.

CEO, Bright Ideas Consulting

Amazing app development service. CompletApp helped us build an app that truly represents our brand.

James P.

Operations Manager, GreenTech Solutions

The perfect app for our business. We did not have the technical know-how to build an app ourselves, but CompletApp made the process so simple.

Laura R.

CTO, StyleSquad

Great template and support. I purchased the custom chat template for FlutterFlow and it has been a game changer.

Alex H.

FlutterFlow builder

Process

A seamless 4-step journey

  1. 01

    Discover

    We dig into your goals, users, and market to define exactly what to build.

  2. 02

    Design

    High-end UI and UX, mapped and prototyped before a line of code is written.

  3. 03

    Build

    Rapid, iterative development with weekly previews you can actually click.

  4. 04

    Launch

    Testing, store submission, and a smooth, fully supported go-live.

Inquiries

Frequently asked questions

Most MVPs go from concept to a functional, high-fidelity product in around 4 weeks. We focus on the core value loop first so you reach market quickly.

Flutter for cross-platform apps, React and Astro for web, Firebase and Supabase for backends, Stripe and RevenueCat for payments, plus OpenAI and Claude for AI. We pick the right tool for each job.

Every project is scoped individually, but we always agree a fixed price before we start. No open-ended hourly surprises. Book a free discovery call for an estimate.

Yes. We offer ongoing maintenance and growth packages to fix issues, add features, and evolve your product as your users and the platforms change.

We grew out of FlutterFlow and now build with full-code Flutter and modern web stacks for more control and performance. Our FlutterFlow templates are still available in the Templates section.

You own your code and accounts from day one, so you are never locked in. For larger builds we agree handover documentation up front, and you can take the project anywhere if you ever need to.

You do. On full payment, all rights to the application and its code transfer to you, with no lock-in to us or any platform.

We agree a fixed scope and price up front and work in milestones. If you are not satisfied after the first milestone, you are under no obligation to pay anything further.
Final step

Ready to build your product?

Let us turn your idea into a living product. Book a free discovery call and get a clear scope, timeline, and fixed price.

Book your free call Start your project
Or book us inside Frendex, the booking app we built

Free 30-minute discovery call. Fixed scope and price agreed up front. No obligation after the call.

Get in touch

Tell us about your project

Fill in the form and we will reply within 24 hours on business days.

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