For US founders building with Lovable, Replit or Base44

You built the prototype.Let’s finish your app.

Built something with AI, but login, payments or a key feature still won’t work? Show Joseph where you’re stuck. Get a clear diagnosis, a written plan and a scoped path to launch. No technical background needed.

US$250 launch review, credited toward a US$3,500 scoped sprint when your project fits.

10 business days of implementation after kickoff and prerequisites are ready.

Book a free 15-minute fit call

Meet Joseph. Confirm fit. No payment to book.

Joseph Kim

Built by Joseph Kim

5,000+ downloads across our own apps.

Our own published productsExplore the work
LevelUp, built by Joseph KimLevelUp
Flirt, built by Joseph KimFlirt
Mustard, built by Joseph KimMustard
FlutterRevenueCatSupabase

Built, shipped and used by real people.

Joseph built LevelUp, Flirt and Mustard: our own mobile apps, with 5,000+ downloads across them. The work includes subscriptions, purchase restoration, login and account access. These products were built with Flutter, RevenueCat and Supabase; the review establishes how that experience fits your AI-built app.

Our product · Beauty & wellness

LevelUp

View on the App Store

From purchase to premium access.

RevenueCat purchase and restore flows, entitlement checks, and access re-sync after a confirmed purchase.

Relevant when a payment succeeds but premium access has not refreshed.

US$8,859.63 in RevenueCat-tracked revenue.

All time through October 23, 2026. After refunds, before store fees and taxes.

View the revenue export
Our product · AI conversation app

Flirt

Subscriptions inside a real product.

Flutter subscription integration with RevenueCat, purchase restoration, and customer entitlement handling.

Relevant when purchase and restore behavior need to work together.

Our product · Faith & personal growth

Mustard

View on the App Store

The right access for the right account.

Supabase authentication, account-scoped subscription state, and regression checks around account access.

Relevant when signing in or switching accounts changes access incorrectly.

Public technical talk · Dev KoreaJoseph Kim: Supabase MVP essentialsWatch the talk

Turn “almost working” into one working user journey.

You have a Lovable, Replit or Base44 build you can show us. We trace what breaks, keep the working parts and agree one outcome you can verify before accepting the work.

Best fit: you know who the app is for, can approve the work and provide feedback within one business day, and have US$3,500available for a fitting completion sprint.

Inspect first. Agree the scope. Then build.

The launch review is the first paid step. You approve the scope and start date before committing to implementation. All prices are in US dollars.

01 / Launch review

US$250

One-time fee · credited toward a fitting sprint

Know what is blocking the release and what should happen next.

  • Up to two hours inspecting your existing build
  • Written findings and the checks actually performed
  • What to keep, what to change, and remaining uncertainty
  • A scoped recommendation and clear next step

Findings within two business days after payment and access are confirmed. No implementation included. Keep the report whether or not you proceed.

02 / App Completion Sprint

US$3,500total

Includes the US$250 review · 10 business days

One agreed release, offered only when the reviewed scope fits.

  • Written deliverables, exclusions, and acceptance checks
  • Implementation and verification of the agreed user flow
  • Progress demonstrations around days 3 and 7
  • Agreed source changes, setup notes, and handover
  • 7-day correction window against agreed checks

Starts after kickoff and prerequisites are ready. Larger work is quoted separately. Platform restrictions, third-party fees and approval timing are discussed before implementation.

One total.
Three payments.

Launch review
US$250
Implementation kickoff
US$1,500
Agreed acceptance
US$1,750

Total: US$3,500, including the review credit. If you stop after the review, you pay only US$250. Any applicable tax is stated before payment.

A decision you can act on.

The review records what we checked, what we found, and what remains unknown. You get a keep/change recommendation and a proposed release scope before committing to development.

See a sample launch reviewIllustrative format · not a client result or a diagnosis of your app

Example blocker

Your AI-built app accepts a test payment, but the user still cannot access the paid feature.

Checks to perform

Trace the payment result, account mapping and access update. Check the agreed behavior after sign-out and sign-in.

Findings & uncertainty

Record observed results and evidence, separate confirmed causes from hypotheses, and list anything not tested.

Scope & acceptance

Agree the correction and verify that a test payment grants the intended access to the correct account. Record the steps and results so the founder can check the outcome.

A clear path from blocker to handover.

  1. Check the fit.

    A free 15-minute call about what you built, what is stuck, your deadline and your budget.

  2. Inspect the build.

    US$250 for up to two hours of review, written findings, and a scoped recommendation.

  3. Agree the outcome.

    Approve deliverables, exclusions, acceptance checks, payments, and the start date.

  4. Build and verify.

    10 business days for a fitting scope, with progress demonstrations around days 3 and 7.

  5. Take it forward.

    Get the agreed changes, setup notes and a walkthrough, including how to maintain your app.

You work directly with Joseph. We agree scope changes before doing extra work. After handover, further improvements can be planned as another optional, scoped sprint.

Clear expectations, upfront.

Is this right for my app?

This offer is for a US-based nontechnical founder with an existing Lovable, Replit or Base44 prototype, a specific blocker and a completion budget of US$3,500. You should be able to show the app and authorize project access. On the free call we check the platform, access and intended outcome before offering the paid review. New ideas, full rebuilds and large feature lists need a separate scope.

Do I need to understand the code?

No. Show us what should happen and what actually happens. Joseph explains the findings in plain language and shows how to check the agreed outcome. You work directly with him from the fit call through handover. He is based in South Korea; choose an available time in your timezone when booking.

Do you keep my existing code?

We inspect what works and recommend what to keep or change. A rewrite is recommended only if the findings justify it. We agree where changes will live, how your platform will be used and how you can maintain the app. If platform restrictions or missing access prevent the work, we explain that before selling implementation.

Is the review included in the US$3,500?

Yes. If your reviewed scope fits the sprint, payments are US$250 for the review, US$1,500 at implementation kickoff, and US$1,750 when the agreed acceptance checks are met. That totals US$3,500. If you stop after the review, you pay only US$250 and keep the findings. No implementation is included in the review. Prices are in US dollars; any applicable tax is stated before payment.

What happens if the work is too large for one sprint?

We explain the findings and propose a smaller release or a separate quote. You decide whether to proceed. The sprint covers the written scope, not every unfinished feature or unrelated defect in the app.

When does the ten-business-day timeline start?

After scope approval, kickoff payment, the agreed start date, and the required access and materials are ready. The timeline assumes feedback within one business day and pauses while we wait for access, materials, or your decisions. We agree your start date before you commit to implementation.

What does launch include?

We agree the user journey, environment and deployment or release work in writing. You receive evidence against the agreed checks and a handover. Platform subscriptions, hosting, API usage, payment processing and other third-party fees remain yours. Platform or app-store approval and third-party review timing are outside our control.

Who owns the code, and what happens after handover?

You retain ownership of your app and accounts. The sprint includes the agreed source changes and setup notes after full payment. For 7 days after handover, we correct reproducible failures against the agreed acceptance checks. New features and unrelated problems are separate work. Further sprints are optional and scoped separately.

What should I bring to the free call?

Bring your app or preview link, the tool you used, the one thing you cannot finish, your target launch date and your completion budget. Screenshots are fine if the project is private. You do not need to diagnose the code. Do not share passwords or private credentials in the booking form; we agree access after confirming fit.

Show me where your app is stuck.

Show Joseph what you built in Lovable, Replit or Base44 and the part you cannot finish. We’ll confirm access, the outcome, timing and budget. Decide on the paid review after the call.

Book a free 15-minute fit call

15 minutes · Google Meet · No payment to book

US clients · Work directly with Joseph in South Korea · All prices in USD

What happens when you book?

  1. Choose a time in your timezone on Cal.com.
  2. Share your app or preview, the tool you used, the main blocker, target date and completion budget.
  3. Receive the calendar invitation and Google Meet details by email.

Bring screenshots if the app is private. Share credentials only through the access process we agree after confirming fit.

Questions or no suitable time? Email Joseph.