Custom software built in Miami, FloridaAbout App369
App369 is a software development company based in Miami, Florida, founded by developer Simon Dziak.
- Fiverr
- 5.0 · 127 reviews
- Own product
- Workspace369
- Fixed-price offers from
- $450
Who builds your app
App369 is one developer, so you always work with the person writing the code.
Simon Dziak
Founder & Lead Developer
Software engineer and founder of App369. Simon builds every client project himself and also built and runs Workspace369, a production Flutter and Firebase platform with a native iOS app.
I also run Client Work HQ, where I publish practical CRM reviews, pricing comparisons and buying guides for freelancers and service businesses.
Founder facts
Fiverr figures carry the date they were read; the rest are facts about the business.
- Fiverr rating
- 5.0 from 127 reviews
- Read from the public profile on October 30, 2026.
- First Fiverr review
- October 2020
- The oldest of the 126 public reviews copied on October 13, 2026.
- App369 LLC
- Registered 2021
- A Florida limited liability company, based in Miami.
- Own product
- Workspace369
- Flutter and Firebase, with a native iOS app on the App Store since 2024.
- Platforms
- iOS, Android, web, backends
- IOS and Android apps (Flutter, with native Swift on iOS), web apps (Vue, Nuxt, React), and backends and APIs (Node.js and TypeScript on Firebase and Google Cloud).
Our story
App369 LLC was registered in Florida in 2021 and is based in Miami. It is one developer, Simon Dziak, building mobile apps, web apps, backends, AI features and payments for clients across the United States.
Simon also built and runs Workspace369, a Flutter and Firebase platform for freelancers and small service businesses, with a native iOS app live on the App Store. App369 uses the same stack for client work and builds AI features on Google Vertex AI.
Smaller jobs are fixed-price offers, with the price, scope and delivery time on the site, paid upfront. Custom builds start with a scoping and are quoted in writing with their payment schedule.
How working with App369 works
Prices in public
Fixed-price offers list their price, scope and delivery time on the site. The instant quote gives a price range in a minute.
One developer
You work directly with the developer writing your code, in writing, with no account managers in between.
The right tools for the job
The stack fits the job: Flutter, Swift or Kotlin for mobile, Vue/Nuxt or React for web, Node.js with Firebase on the backend, plus Stripe for payments and LLM APIs for AI features.
Our milestones
Key dates for App369 and the software it runs.
App369 LLC Registered
Registered App369 LLC in Florida, now based in Miami.
Workspace369 on the App Store
Founder Simon Dziak launched Workspace369, a Flutter and Firebase platform for freelancers and small service businesses, with a native iOS app.
AI Features in Production
Added AI features built on Google Vertex AI to production software, the same stack App369 now offers to clients.
Fixed-Price Offers
Introduced fixed-price packages for smaller jobs, paid upfront. Custom builds are quoted in writing with their payment schedule.
The technology stack
- Flutter
- Swift
- Kotlin
- TypeScript
- Node.js
- Vue.js
- React
- Firebase
- Google Cloud
Start with Your Project Details
Simon replies by email, usually within one business day. Share your project scope and receive technology recommendations and a preliminary cost estimate. Prefer to talk? Consultations are $100 per 15 minutes, paid upfront.