iOS and Android, with a real backend. Fixed price. Your code.
For a focused app. Store review usually adds 1–2 days. Audit fee credited to your build.
Apps and platforms I've built, for founders and for my own companies
YC startup
WeJammin
Emtropy LabsThe last 20% of an app is where the money and the trust live. It's also where AI-built apps stall.
Who can see what? In one 2025 study, 170 of 1,645 Lovable-built projects exposed user data.Lovable disputes the finding. CVE note
In-app purchases, subscriptions and webhooks that fail quietly cost you real revenue.
Apple rejected 2.09 million of 9.1 million submissions in 2025.
Small phones, bad signal, edge cases: the crashes your first users find for you.
That last 20% is my job. You keep the vision; I make it hold up.
Most quick builds are disposable: one tangled codebase, keys inside the app, nothing another developer could pick up. Every ProSofts launch ships as a Launch Box, the full set of parts a real product needs. Open it and check.
A native iPhone and Android app from one codebase, a reusable design system, same-day fixes over the air.
LaterNew screens take days, not weeks.
A Node API and Supabase (Postgres database, sign-in, storage), with per-user data rules, background jobs, and separate test and live environments.
LaterAdd a web app, partners or AI features without a rebuild.
Subscriptions, trials and one-time purchases through Apple and Google, with verified webhooks synced to your backend.
LaterClean revenue data and no double charges.
Automated tests on the app and the API, crash alerts, analytics on sign-up, first use and purchase.
LaterYou hear about problems before your users do.
A store listing built for search, privacy labels, submission, code in your GitHub, accounts in your name, docs and a recorded walkthrough.
LaterAny good engineer can take over, so you're never locked in.
The same foundations I used to run a fintech backend through 5× growth with zero downtime.
Why payments are in the box from day one: apps with a hard paywall convert about 10.7% of downloads to paid, against 2.1% for freemium (RevenueCat, State of Subscription Apps 2026).
YC startup
They had Figma designs. I prototyped a new design in Claude in 30 minutes; they chose it, and it went through my pipeline into the full exchange app.
ServX24
One Expo app for employees and drivers: book a cab, track it live on the map, SOS and trip sharing, built on ServX24's existing ERP.
Updraft
Expo screens built on a Figma design system shared by the app and the web. Work done as a senior engineer at Updraft.
WeJammin
A music video app: design, on-device FFmpeg video editing, native audio engine, AI tools, backend, store launch and growth were all mine. Install count from Google Play Console.
“Streaming gives you exposure, but FanFliQ gives you ownership. My fans directly support my music, and I've built a dedicated core audience who buy my exclusives and interact with every release. If you're an artist, this is a no-brainer!”
MC KodeArtist on FanFliQNo discovery call needed to know what it costs. Buy the first step online.
$500one-time
from$6,500
From idea or prototype to approved, live and taking payments. Your full Launch Box included:
from$1,000/month
Also: app blueprint $1,000rescue sprint from $3,000store & paywall kit $1,750See all prices
The average agency app project costs $90,780 and takes about 11 months (Clutch, 2026).
I'm Proshanto Gupta. For 10+ years I've been the engineer startups call first, and the one who gets paged when it breaks. I took FanFliQ from idea to first paying user in 21 days and ran a fintech backend through 5× growth with zero downtime. Most studios are frontend shops; I've spent a decade on the backends that keep apps standing. Now my AI pipeline does the heavy lifting, and I make every call that matters. You'll never be handed to an account manager.
A 15-minute call is there if you want one.
Book a free 15-min call → Or email pro.gupta28@gmail.comUsually, yes. Most are web apps, which Apple often rejects as "just a website". I turn yours into a real native app, keeping your design, logic and data.
For a focused app (one core flow, about 10–20 screens), yes: built, tested and submitted in 2 weeks. Bigger apps get phased, and you'll know before you pay.
I fix anything in scope for free until it's approved.
Yes, from day one. It lives in your GitHub, and the apps live in your store accounts. With the docs and recorded walkthrough, any good developer can pick it up later.
No. Get the launch audit online ($500). A 15-minute call is there if you want one.
Yes. Every launch includes a Node and Supabase backend (database, sign-in, storage), plus subscriptions, trials and one-time purchases through Apple and Google, all set up in your own accounts.
Care & grow keeps the app healthy and improves conversion, month to month. Cancel anytime.
With a business developer account, usually. New personal accounts must run a 14-day test with 12 testers first.
Agencies average about $90,780 (Clutch). A focused launch here starts at $6,500, fixed.
I keep daily hours that overlap the US workday, send updates every day and join a weekly call. You're invoiced in USD.
Find out in 48 hours exactly what it takes to get your app approved, live and earning.
Audit fee credited to your build · NDA on request
Credited to your buildFree · no call needed
