Startup apps

From idea to paying users.

From idea to a product people pay for — MVPs built fast on a stack that scales, so you never have to rebuild after traction. Free working prototype in 1 day, then a production release at a fixed price and date.

Web & Mobile apps

Get your free prototype 30-min call · no commitment

dashboard.startup.io

Monthly recurring revenue

$48,200

▲ 32% MoM

7d30d12m

checkout.tsAI

export async function subscribe(user, plan) {

const session = await stripe.checkout.create({

customer: user.stripeId,

price: plan.priceId,

})

track('subscribe_started', { plan: plan.id })

return session.url

}

Senior review · approved

Pipelinemain

Build
Testspassed
Senior review
Previewdeployed
Productionlive

Buildto launch

Day 1Week 1Week 2Week 3Live

Your MVP is liveFirst paying usersnow

At a glance

One product. One price, one date.

The essentials, before you book a call.

UDEX builds Startup apps for founders and product teams. From idea to a product people pay for — MVPs built fast on a stack that scales, so you never have to rebuild after traction. AI writes the code, tests and CI/CD, while senior engineers own the architecture and review every change.

1 dayFree prototypeNo payment, no commitment

FixedPrice and dateAgreed before we start

100%YoursCode, repository and accounts

Platform: Web and mobile MVPs
Ships to: Production
Stack: Next.jsReact NativeConvexStripeVercel
Quality: Senior review on every change, automated tests, CI/CD

How it works

Idea to production. In three steps.

AI does the heavy lifting. Senior engineers make every decision that matters.

01Day 0
Share the idea
A 30-minute call. We agree on the core flow, the scope and a fixed release date.
02Day 1 → release
AI builds, senior engineers decide
AI writes the code, tests and CI/CD. Senior engineers set the architecture and review every change. Your prototype is ready on day 1.
03Release day
Ship to production
The release goes live, and the code, repository and accounts are handed to you.

Who it’s for

Built for founders and product teams.

Here is where it works best, and where it doesn’t.

Pre-seed and seed founders

A real product for users and investors, not a deck.

Non-technical founders

Senior engineers make the technical calls and explain them in plain words.

Founders preparing a round

Traction and a live product before you pitch.

AI-first startups

AI features built into the product from day one.

Marketplaces

Both sides of the product with payments.

Founders outgrowing no-code

Rebuild the MVP on a stack that scales.

Not the right fit

Ideas without a defined first user or problem yet.
Products that need years of R&D before launch.
Certified compliance from day one, such as HIPAA or PCI audits.
Open-ended hourly work without a defined first release.

How we work

Six stages, one team.

All services

Pricing

Start free. Ship at a fixed price.

Two steps. The prototype costs nothing, and the release costs exactly what we agree.

Prototype

Free1 day

A working prototype of your core flow to test with users and show investors.

Key screens and the main user flow
Working on real devices and browsers
No payment, no commitment

Get the free prototype

Release

Fixed priceand date, agreed upfront

A production release, shipped to production, that you fully own.

Next.js, React Native, Convex and the features agreed on the call
Automated tests, CI/CD and senior code review
Release to production and 100% code ownership

Start with a call

Fixed means fixed. No hourly billing and no surprise invoices: anything new is priced before it is built.

Book a call

Thirty minutes. Then your prototype.

Walk us through the idea, and we will scope the core flow and build your free prototype the next day.

Book a 30-min call

FAQ

Questions, answered.

Straight answers about cost, timing, quality and ownership.

How much does it cost to build a Startup app?

The price is fixed for the agreed scope and set before work starts. You first get a free working prototype of the core flow in 1 day, then a fixed price and release date for the production version.

How long does it take to build a Startup app?

A working prototype takes 1 day. The production release date is agreed upfront and depends on the scope; AI speed with senior engineering makes it much faster than classic development.

Will we have to rebuild after traction?

No. The MVP is built on a production-ready stack that grows with you.

Do you help with product decisions?

Yes. We start with discovery and a prototype, and challenge scope so you ship what matters first.

Can you add payments and analytics?

Yes. Payments, onboarding and analytics are standard parts of an MVP.

Is the prototype really free?

Yes, with no commitment. After a 30-minute call we build a working prototype of your core flow in 1 day, and then you decide whether to continue to the release.

Will the price go up during the build?

No. The price is fixed for the agreed scope. Anything new you want to add mid-build is priced separately and built only after you approve it.

Who owns the code?

You do, 100%. The source code, repository and accounts are yours, and the release ships to production under your name.

Is AI-written code safe to ship to production?

It ships only after senior review. Senior engineers own the architecture, security and code quality, and automated tests run on every change.

In practice