How long does it take to build a mobile app?

Most MVPs take 4-8 weeks from kickoff to launch. More complex apps with integrations, custom backends, or compliance requirements typically take 14-20 weeks. We'll give you a realistic timeline during our initial consultation — we don't overpromise to win the deal.

How much does mobile app development cost?

We offer competitive European rates without compromising on quality: Simple apps (basic features, single platform): ~$9,360 – $17,550 Medium complexity (user accounts, payments, API integrations): ~$17,550 – $40,950 Complex apps (real-time features, multiple integrations, admin dashboards): ~$40,950 – $70,200 Enterprise solutions (compliance requirements, advanced security, legacy system integration): $70,200+ We provide detailed fixed-price quotes after understanding your requirements, no surprises in the middle of the project. With 13+ years of experience and 300+ delivered projects, we know how to scope accurately.

Do you build for both iOS and Android?

Yes. We typically use cross-platform frameworks like React Native or Flutter, which let us build for both platforms simultaneously. This reduces cost and development time by 30-40% compared to building two separate native apps.

What industries do you work with?

We don't specialize in one industry. Over the past 13 years we've built apps for e-commerce stores, SaaS startups, HR companies, hotels, B2B platforms, and more. If you need a mobile app, a web platform, or custom software that actually works in production, we can probably help. The common thread is clients who need reliable delivery, not the cheapest quote.

What does your development process look like?

We work in 2-week sprints. At the end of each sprint, you see working software, not slides or mockups. You'll have a dedicated point of contact, access to our project management tools, and bi-weekly demo calls. No disappearing for months and hoping for the best.

Will I own the source code?

Yes, 100%. You own everything we build including source code, documentation, designs, deployment configurations. No licensing fees, no lock-in. If you want to take the code to another team tomorrow, you can.

How do you handle communication?

You'll have direct access to the engineers working on your project and not just a project manager relaying messages. We use Slack for day-to-day communication and scheduled video calls for demos and planning. Most questions get answered within a few hours during business hours.

What if I need changes after launch?

We offer ongoing support and maintenance packages, but you're not locked in. Since you own the code and we document everything, any competent development team can pick up where we left off.

What technologies do you use?

Mobile:React Native, Flutter, Swift (iOS), Kotlin (Android), Unity Engine and sometimes just WebView Web: PHP ,React, Next.js, Node.js, Python Backend: AWS, Google Cloud, PostgreSQL, MongoDB We choose the stack based on your needs, not what's trendy. We'll recommend what makes sense for your timeline, budget, and long-term maintenance.

Can you work with our existing codebase?

Yes. We regularly take over projects from other teams. We'll start with a code audit to assess what's salvageable and what needs rebuilding. We'll be honest sometimes it's faster to rebuild than to fix.

Do you handle UI/UX design?

Yes. Our design team handles user research, wireframes, prototypes, and final UI design. Good design isn't optional apps that look dated or are hard to use don't get traction, no matter how solid the code is.

How do you ensure app security?

Security is built into our process, not bolted on at the end. We use encryption for data at rest and in transit, secure authentication, and follow OWASP guidelines. For healthcare or financial apps, we can implement HIPAA or PCI-DSS or WCAG or GDPR compliance requirements.

How do I know if we're a good fit?

We work best with clients who: - Have a clear business problem they're trying to solve - Are ready to invest in quality (not looking for the cheapest option) - Want to be involved in the process, not just hand off requirements and disappear - Need software that works reliably in production

What do you need from me to get started?

For an initial consultation, just a rough idea of what you want to build and your goals. We'll ask questions to fill in the gaps. For a formal proposal, we'll need more detail but we'll guide you through that process.

How do I get a quote?

[Contact us](/contact) with a brief description of your project. We'll schedule a 30-minute call to understand your needs, then follow up with a detailed proposal within 3-5 business days.

What if I'm not happy with the work?

We demo working software every two weeks. If something isn't right, we catch it early and fix it not three months later when it's expensive to change. If there's ever a fundamental disagreement, you own the code and can walk away.

What if my requirements change mid-project?

They will, that's normal. Our sprint-based process is designed for this. We'll discuss the impact on timeline and budget, and you decide whether to proceed. No change requests disappear into a black hole.

What happens if a key team member leaves?

We have engineering teams across multiple locations and other regions, so there's always someone ready to step in. We document everything properly and use standard code practices, so knowledge doesn't get stuck in one person's head. In 13 years, we've never had a project stall because of team changes.

How does pricing work?

We offer two models: 1) Fixed-price projects: Best for well-defined scopes. You know the total cost upfront. 2) Time & materials: Best for evolving projects. You pay for actual hours worked, with full transparency. Most clients start with fixed-price for the MVP, then move to time & materials for ongoing development.

What are your payment terms?

Typically 30-40% upfront, with remaining payments tied to milestones. We don't ask for 100% upfront, and we don't invoice for work you haven't seen.

Do you offer payment plans?

Yes. We can structure payments across the project timeline to help with cash flow. Let's discuss what works for your situation.

Custom iOS & Android Development for US Businesses

Mobile App Development
Company for iOS & Android Systems

Building iOS & Android systems for startups and enterprises, from MVPs to scalable, production-ready apps.

MVPs That Fail to Scale

FQB rebuilds MVP apps into scalable products with stable APIs and production-grade performance.

Unstructured AI-Generated Code

Audit and refactor rushed codebases into maintainable, compliant systems that can grow safely.

View Mobile App Development Services

Five Quantum Bits - Mobile App Development

Five Quantum Bits - iOS & Android Apps

Five Quantum Bits - Startup & Enterprise Solutions

Five Quantum Bits - US-Focused Mobile Team

US-Focused Mobile App Development Company

Build iOS & Android Apps Scale From MVP to Production

We build and maintain production-grade iOS & Android systems for teams that can’t afford failure. Five Quantum Bits is a senior mobile engineering company building high-risk, high-value mobile systems for US businesses that need certainty, not experiments.

Learn More About Us

Explore Our Mobile App Development Expertise

Trusted by Public Institutions & Growing Businesses

Building a software product as a non-technical founder is hard. Even more so when timelines slip, communication breaks down, or the team you hired slowly disappears.

We’ve seen this happen many times, because the team was overstretched, sometimes because the product wasn’t designed to scale, and sometimes because no one was truly accountable for the outcome.

That experience shaped how we work.

Five Quantum Bits was built around reliability and trust. We work in small, multidisciplinary teams that stay with your product from design through delivery. You own the source code. You always know what’s being built, why it’s being built, and what comes next.

Our goal isn’t just to ship software, it’s to make sure what we build holds up in real use. We work closely with our clients, communicate clearly, and take responsibility for the end result, not just the task list.

We aim to be the team you don’t have to worry about.

Learn More About Us

Why Choose Us

Reliable iOS & Android Delivery

100% Source Code Ownership

You own everything. Full source code, complete documentation, deployment keys. Take it anywhere, modify it anytime. Unlike agencies that lock you into maintenance contracts, we hand over the keys.

Full Source Code Ownership

Flexible Architecture

Predictable Delivery

Speed without sacrifice. Our agile sprint process means you see working features every 2 weeks. No 6-month wait to see if it works.

Bi-weekly demos & feedback

Milestone-based payments

Delivery timelines agreed upfront

Built to Scale

We don't build throw-away MVPs. Your app is architected for 10k users on day one, 1M users by year two. Cloud-native, auto-scaling infrastructure from the start.

Scalable architecture for growth

Cloud-ready (AWS / GCP)

Reliability & monitoring best practices

Security-First Development

Security-first engineering with secure defaults (encryption, secrets management, least privilege). Compliance support for GDPR/CCPA and industry requirements.

Data Encryption

Compliance Ready

Our Services

Intelligent Solutions for
Modern Business

Mobile Apps (iOS & Android)

Captivate your audience with native and hybrid mobile apps. We build high-performance, user-centric experiences that elevate your brand across all devices.

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Custom Software Solutions

Tailored solutions designed to meet your unique business needs. We create powerful software from scratch to optimize workflows and boost efficiency.

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Website Development

Your website is your 24/7 salesperson. We build custom sites that load in under 2 seconds, work flawlessly on mobile, and are built to grow with your business.

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Talk to a Senior Engineer

Get a project assessment in 24–48h

185+ Projects delivered

Our Projects

Showcasing Our Success
Through Innovative Projects

Custom E-commerce platform

A local floral shop that has changed the rules of the game and has been successfully running since 2012.

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Custom B2B SaaS Platform SmartBizz

By utilizing a Custom B2B SaaS Platform architecture, Five Quantum Bits enabled a seamless flow...

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Kindergarten Website Development

Our team responded immediately to new legislative requirements demanding that all educational institutions in ...

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Clients Feedback

What People Say About Us

We are a small company, and building our own application was a serious step and a real risk for us. Five Quantum Bits fully met our expectations. They took the time to deeply understand our idea, suggested practical solutions, and delivered a product that truly works for the business. Communication was 10/10 and In the end, we received a stable, user-friendly application and a partner we would confidently work with again and recommend to other small businesses.

Alexander C.

Founder at SmartBizz

I reached out to Five for a consultation while I was still planning to start my business and looking for the right partners. I wasn’t ready to build anything yet, but the consultation alone made a strong impression. The team gave honest, practical advice, asked the right questions, and helped me see the idea more clearly. When the time comes to move forward, I already know I’ll be working with Five Quantum Bits Team.

Andrew Mocanu

Manager & Marketing

I’ve worked with other developers before and was left with a broken product and a lot of frustration. When I came to FQB, they quickly understood the issues and fixed what others failed to deliver. Clear communication, no excuses, and real results. Everything finally worked as it should. I’d confidently recommend FQB to anyone who’s had a bad experience with previous teams.

Sophia H.

ZWAP

I’ve always run my home baking business in a very simple way and never felt comfortable with technology. Anything digital seemed complicated and stressful to me. With FQB, everything felt much easier. They explained things in a way I could actually understand and were very patient with me. They helped me set things up so I could take orders more easily and stay in touch with customers without confusion. Because of their help, my baking business has grown and become more organized. I feel more confident now and less afraid of using new tools. I’m really thankful to FQB and would recommend them to anyone who feels the same way about technology as I do.

Maria S.

Bunica’s Oven

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