Klaus Custom Studio · Seaside, California

One developer.
Real apps.
Shipped.

KCS is a solo studio out of Seaside, CA. I build Flutter mobile apps and web products from idea to App Store — designed, coded, and launched by one person who actually gives a damn about the work.

By the Numbers
6
Products live or launching
QR Party, RollCall, Wrench Market, Scaffold, TestYard — all built solo from concept to launch.
iOS
+ Android. Both stores.
App Store submissions, TestFlight, Google Play — testers welcome on both platforms.
0
Agencies involved
No middlemen. No account managers. Just the developer who built it.

The Work

// Six Active Products
// For Everyone
QP
Live on Android
QR Party
Event RSVP and check-in via QR code. Real-time guest lists, instant access. Zero paper.
Flutter · Firebase · iOS + Android
WM
In Development
Wrench Market
On-demand mobile mechanic marketplace. Verified techs. Escrow payments. They come to you.
Flutter · Firebase · Stripe · Plaid · Claude API
// For OHV Riders
RC
In Testing
RollCall
OHV ride coordination with real-time GPS tracking, trail conditions, and fire alerts. Built for dirt.
Flutter · Supabase · Mapbox · Firebase · FCM
// For Developers
SC
Live · Taking Payments
Scaffold
AI-powered build packets for developers. Structured prompts that ship real products faster.
Next.js · Supabase · Stripe · Claude API
TY
Live · May 21 2026
TestYard
Beta testing marketplace. Developers list apps, testers give real feedback. Quality scored by AI.
Next.js · Supabase · Claude API · Resend
NS
Dev Tool · Personal Build
NeonShell
Mobile terminal for Claude Code. Type or speak commands from your phone, they run on your PC through a secure tunnel.
Flutter · Node.js · ngrok · Claude API · Voice Input
// Work Together

Have an
idea?
Let's build it.

You don't need a big team. You don't need an agency. You need someone who can take an idea from a napkin sketch to the App Store — and actually give a damn about how it turns out.

Bring the vision. I'll handle the rest — architecture, design, development, deployment. All of it.

Find Me on Upwork ↗
What I can build for you
  • iOS + Android apps — Flutter, shipped to both stores
  • Web products — Next.js, fast, scalable, production-ready
  • Backends + databases — Supabase, Firebase, real-time ready
  • AI-powered features — Claude API integration, chat, vision, search
  • Payments + marketplaces — Stripe Connect, escrow, subscriptions
  • Maps + location — Mapbox, GPS tracking, geofencing
Flutter · Dart · Next.js · TypeScript
Supabase · Firebase · Stripe · Claude API · Mapbox
Studio
Philosophy

"No agencies. No account managers.
No one between you and the person
actually writing the code.
Just me."

KCS is a solo development studio in Seaside, CA. One developer handles everything from architecture to deployment. No handoffs, no miscommunication, no agency markup. You work directly with the person who built it.

Let's build
something.

Freelance inquiries, product partnerships, or just want to talk shop — reach out directly. No forms, no bots.

Direct Line
admin@klauscustom.com
Klaus Custom Studio LLC
Seaside, California
D-U-N-S 145012101