StockholmApp & Custom Software Development in Stockholm
Software development for Stockholm. We build professional mobile apps and web platforms for the Nordic unicorn factory, home to Spotify, Klarna, and King.
App369 is a founder-led software studio based in Miami, Florida. Simon builds custom mobile apps, web platforms and AI features for businesses in Stockholm and beyond, working remotely on Eastern Time.
- Fiverr
- 5.0 · 127 reviews
- Own product
- Workspace369
- Fixed-price offers from
- $450
Same fixed prices wherever you are
Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.
- App Fix Ticketfrom $450One reproducible bug in an existing mobile or web app, diagnosed and fixed.
- AI-Built App Rescuefrom $450A Lovable, Bolt or Cursor app checked end to end in 3 days, then its worst problems fixed at a fixed price.
- Web App MVP Sprintfrom $6,000A scoped web app MVP in Vue/Nuxt or React, with a fixed quote after a $450 written scoping.
- Monthly Dev Subscriptionfrom $1,495/monthOne development request at a time, most back in about 2 business days. Pause or cancel anytime.
Why App369
Why Stockholm Businesses Choose App369
What Stockholm teams should know before working with App369.
Serving Stockholm, the Nordics, and the Baltics from Europe's unicorn capital, with more billion-dollar startups per capita than any city outside Silicon Valley
Focus on fintech and gaming
GDPR-aware development for Swedish and EU data protection standards, including PSD2 for financial applications
What Simon builds
Software Development Services in Stockholm
From Kista Science City to Södermalm's creative tech district, we build software that matches the ambition and quality of Stockholm's legendary startup ecosystem.
Mobile Apps
iOS and Android apps built with Flutter from one codebase, from concept to App Store launch.
- iOS & Android
- Cross-Platform
- App Store Optimization
- Maintenance & Updates
Web Development
Fast websites and web applications, built for search and for phones first.
- Custom Design
- E-Commerce
- SaaS Applications
- SEO Optimization
Custom Software
Internal tools, integrations and back-office systems engineered around how your team already works.
- Enterprise Development
- API Integration
- Cloud Migration
- Technical Consulting
How it works
The 4-Phase Development Process
A written scope and four clear phases keep Stockholm projects predictable.
Discovery
Understanding your vision, goals, and market requirements through stakeholder interviews and competitive analysis.
Design
Creating clear UI/UX with interactive prototypes you can click through before the build starts.
Development
Building with Flutter, Vue.js, Node.js, and GCP using 2-week Agile sprints with weekly milestone reviews.
Launch
Deployment to production with crash and uptime monitoring and ongoing maintenance.
Technologies
- Flutter
- TypeScript
- Node.js
- GCP
- Firebase
- Vue
- JavaScript
- Python
Questions
Frequently Asked Questions
How long does a typical project take?
It depends on scope. As a rough guide, a marketing website takes 4-8 weeks, a web application 2-4 months, and a mobile app 3-6 months. Every Stockholm project starts with a written scope and milestone plan, so you know the timeline before any build work starts.
Do you provide ongoing support?
Yes. After launch App369 offers maintenance that covers bug fixes, iOS and Android OS updates, security patches, dependency upgrades and small feature work, so your Stockholm app keeps working as the platforms change.
What's your pricing model?
Fixed-price offers are paid in full before work starts, at the prices published on the fixed-price page. Larger builds start with a paid scoping and are then quoted in writing, with their payment schedule, and start only with your yes.
Can you work with existing projects?
Yes. Simon takes over existing codebases, especially Flutter and Firebase apps, for code audits, bug fixes, new features and migrations. Stockholm businesses with an app that stalled or a developer who left can start with an audit before committing to a larger build.
What technology do you use?
Mostly Flutter for iOS, Android and web apps from one codebase, Firebase and Google Cloud for backends, and Vue/Nuxt for websites. For AI features Simon integrates large language models for assistants, document extraction and automation.
Your Development Partner
Simon Dziak
As founder of App369, I personally oversee every project App369 takes on, from scoping to launch. I build with Flutter, Firebase and Google Cloud, and I also built and run Workspace369, a client-management platform for freelancers and small businesses. Based in Miami, Florida, I serve clients across Stockholm and nationwide.
Start Your Stockholm Project
Fiverr reviews / 95 on app work
What buyers said about working with Simon
“I highly recommend this developer. He helped me create an amazing application, that is definitely going to help my business generate a lot more income. He is fast, intelligent, and hard-working. Look no further, you found the perfect developer for your project.”
Mark, United States, March 2022. App development on Fiverr “Thank you again, Simon, for another QUICK and SATISFACTORY delivery! I highly recommend this seller because he is fantastic! I'm also coming back to buy more services. My requests were a bit over the roof, but his understanding of the task is mouthwatering. Once I saw his delivery, I approved it immediately. And he was very responsive while discussing the details.”
Mark, United States, March 2022. App development on Fiverr “Incredible professional! I am really excited to be working with him on my new application. He will take the time to really understand what your project needs. Simon is the best!”
Mark, United States, March 2022. Custom order on Fiverr
Read the whole story
- Sixteen five-star reviews from one buyer: mobile apps, app design and a Shopify store (Mark, United States)
- A large custom app build, delivered on the back end and the front end (A buyer in the United States)