MG Software · Haarlem
Custom app development that ships
From first idea to App Store or Play release, or a web app that keeps operations moving: MG Software in Haarlem builds software around your business.
Not a standard package you need to adapt, but software that fits how your team works, how your customers think and how your business grows.
We build apps that do not just look good but are technically solid. That means fast load times, flawless operation across devices and an architecture that scales when your user count doubles.
Who do we build apps for?
App development sounds broad, and it is. But the majority of our projects fall into these categories.
Startups with an MVP
You want to validate an idea in the market before investing a large budget. We build a lean MVP with the core functionality you need to test whether your target audience is willing to pay. No features that are 'maybe needed later', but a solid technical foundation to build on.
Businesses with growing pains
Your processes grow faster than your tools can handle. Spreadsheets, separate systems and manual work slow your team down. We build a custom application that centralises your workflow and lays the foundation for further growth.
Organisations with a specific audience
You serve a niche where no standard solution exists. Medical professionals, logistics planners, property managers. The specific requirements of your users demand software that does not come off the shelf but is tailor-made for their daily practice.
Existing businesses going digital
You have a successful business but your digital presence lags behind. An app or platform can improve your customer experience, open new revenue streams or automate existing processes. We help you take that step without disrupting your current operations.
Our process
We work in clear phases so you always know where the project stands, what comes next and when you can steer.
Discovery
Map goals, users and existing landscape. We identify risks and opportunities before any code is written.
Design
Wireframes, clickable prototypes and visual design. You see the product before a developer starts.
Development
Build in two-week sprints with working demos. Every sprint delivers something testable.
Testing & QA
Functional tests, performance checks and security review before your users see it.
Launch
Deployment with monitoring setup, error logging and a rollback plan when needed.
Iteration
Maintenance, version management and iteration based on user data. Software is never done.
Which type of app fits?
The choice between native, web and hybrid directly impacts budget, timeline and user experience.
Native app (iOS / Android)
Maximum performance, full hardware access, push notifications, offline-first.
Two codebases (Swift + Kotlin), higher investment, store review process.
Consumer-facing apps with high UX demands, deep OS integration.
Web app / PWA
One codebase, fast to market, no store dependency, reachable via URL.
Limited hardware access, dependent on browser capabilities.
Internal tools, dashboards, B2B portals.
Hybrid / cross-platform
One codebase, near-native feel via React Native or Flutter.
Slight performance trade-off for complex animations.
Startups validating fast, MVPs that grow into native later.
Technology we use
We choose our stack based on the problem, not based on hype.
React / Next.js
Web & frontend
React Native
Cross-platform mobile
Node.js / Bun
Backend & APIs
PostgreSQL
Relational data
Supabase
Auth, storage, realtime
Vercel / AWS
Hosting & CDN
Stripe / Mollie
Payments
OpenAI / LLMs
AI integrations
What does app development cost?
The honest answer: it depends on scope, complexity and quality requirements. A compact MVP starts at a lower budget than an enterprise app with multiple integrations and compliance needs.
What we can do: give transparent ranges. Use our calculator for a first indication, or read our in-depth guide on app costs in 2026.
Maintenance and continued development
Launching your app is just the beginning. App Stores expect regular updates: new OS versions, security patches, third-party API changes. Without maintenance an app ages faster than most clients expect. We plan this upfront so you are not caught off guard.
We offer retainer contracts that fit your situation. That can be a light package for monthly maintenance and bugfixes, or a comprehensive package including feature development and performance monitoring. The difference is you do not need to start a new project every time.
Version management is a crucial part of continued development. We work with feature branches, staging environments and automated release pipelines. That means updates are tested and validated before reaching your end users, without extra work for your team.
Common mistakes in app development
Over the past years we have seen what goes wrong in app projects. These four mistakes come up most often.
Uncontrolled scope creep
The project starts with a clear idea, but after every feedback round extra wishes pile on. Without clear prioritisation and a defined MVP scope the budget overruns and the deadline keeps shifting. A good discovery phase prevents this.
Skipping the design phase
Jumping straight into code feels efficient but almost always produces more expensive work. Without wireframes and prototypes you discover problems only when they are already in code, and then fixing them costs twice as much.
Choosing the wrong technology
React Native for a game, native for a simple dashboard, or a no-code tool for a complex platform: the technology choice must match the problem. We help you make that trade-off honestly before a single line of code is written.
No maintenance budget
Many clients budget for the build but not for what comes after. Servers, SSL certificates, store subscriptions, OS updates and bugfixes cost money. Expect at least 15 to 20 percent of build costs per year for maintenance.
What makes a good app?
Technology is just the means. A good app distinguishes itself in four areas that together determine whether users come back.
Intuitive UX
Users do not want to read a manual. A well-designed app feels natural: the most important actions are reachable within two taps, forms are short and error messages tell you exactly what went wrong. You only achieve that by testing with real users, not by assuming you got it right.
Reliable performance
Nothing kills trust faster than an app that crashes or responds slowly. We test on older devices, slow connections and peak load. Performance is not an afterthought; it is a design requirement we carry from the start.
Accessibility
An app that does not work with screen readers or is unreadable for colour-blind users excludes part of your audience. We build according to WCAG guidelines and test with assistive technology. That is not just ethically right, it also expands your reach.
Security from the start
Encryption, authentication, authorisation and input validation are not added as a final layer but are part of the foundation. We implement OWASP best practices and conduct penetration tests before your app goes live.
How we collaborate
We believe the best software is created when client and development team work closely together. That is why you do not get a weekly email report but direct access to our project board, daily updates in a shared Slack channel and biweekly demo sessions where you see progress live.
Feedback does not have to wait until the next sprint. If you see something that needs to change, we discuss it the same day. Those short feedback loops prevent us from building in the wrong direction for two weeks and ensure the end result truly matches your expectations.
After delivery we remain available. We are not an agency that closes the project and moves on to the next client. Our retainer clients have a dedicated contact person who knows their application and can act quickly when needed.
Why MG Software?
No middlemen
You talk directly to the developers working on your project. No project manager filtering or slowing information.
Ownership and transparency
You own the code. Repositories, credentials and documentation are handed over. No vendor lock-in.
Dutch team
Based in Haarlem with clients across the Netherlands. No timezone issues, no language barriers.
Full-stack, no loose ends
From database design to deployment: we deliver the full journey. No external UX agency or third-party QA needed.
Further reading
Discover related pages, examples and background articles.
Frequently asked questions
How much does custom app development cost?
Investment depends on platforms (iOS, Android, web), screen count, integrations and maintenance. A focused MVP typically starts lower; enterprise-grade apps with backends and integrations cost more. Use the calculator at /calculator and read our 2026 cost guide on the blog.
How long does it take to build an app?
A first release can ship in a few months when scope and design are clear. Heavier programmes with multiple integrations or compliance needs take longer. We work in sprints with visible increments.
Can you connect existing systems?
Yes. We build API integrations with ERP, CRM, payments and more. See /api-koppelingen for examples such as Exact, Stripe or Shopify.
Native app or web app: what fits?
Native (Swift, Kotlin) helps when you need deep OS integration. Web apps or PWAs often reach market faster and suit internal tools. We recommend based on users, budget and roadmap.
What about maintenance after launch?
Stores require periodic updates; OS and library churn continues. We offer retainers with monitoring, security patches and incremental improvements.
Remote or on-site collaboration?
We are based in Haarlem and work hybrid. Discovery and reviews can be remote or in person with the same delivery quality.
Who owns the code?
You own what we build for you unless contractually agreed otherwise. Repositories and access are handed over cleanly.
How do we get started?
Contact us via /contact or complete the calculator. We schedule a short call, align scope and share a milestone-based proposal.
What is the difference between an app and a web app?
A native app is installed through the App Store or Google Play and runs directly on your phone's operating system. That gives access to features like push notifications, camera and offline use. A web app opens in the browser, requires no installation and works on any device with a browser. For many internal tools and dashboards a web app works perfectly. We help you choose based on your audience and the features you actually need.
Can you improve an existing app?
Absolutely. Not every project starts from scratch. We assess your current app on architecture, performance and user experience and create an improvement plan. Think new interface, faster load times, better integrations or a move to a more modern stack. That way you get more from your existing investment without rebuilding everything.
What if my budget is limited?
Then we start small with an MVP: the minimal version of your app that solves the core problem. Based on real user data we then expand step by step. This approach not only saves money but also helps you learn faster what your users actually need. Many successful apps started exactly this way.
How do you handle privacy and GDPR?
We build privacy in from day one, not as an afterthought. That means data minimisation, encryption, clear consent flows and a data processing agreement. When needed we support you with a DPIA (Data Protection Impact Assessment). We account for GDPR so your app stays compliant without compromising user experience.
Ready to start?
Schedule a no-obligation call. We discuss your idea, ask the right questions and give an honest estimate.