Android & iOS apps
Cross-platform apps with React Native and Expo, native Android, or .NET MAUI. Offline mode, barcode and label scanning, background sync, and signed APK builds ready for your team.
React NativeExpoAndroid.NET MAUI
Available for freelance projects
Hi, I'm Rahul Biswas, a freelance full-stack & mobile app developer.
I build apps people actually use.
Mobile apps, web portals and the backends behind them, from the first screen to the production release. Ordering apps with live tracking, admin dashboards, customer web shops, and everyday Android apps for finance, habits and health.
11apps built
6mobile apps
3mobile stacks
React NativeExpoTypeScriptReactNext.jsAngularFastAPINode.jsPostgreSQL.NET MAUIDockerTailwind CSS
Freelance services
What I can build for you
Hire me for a full product or one piece of it. You get working software, the source code and the docs to run it.
Web apps & portals
Customer portals, web shops, order tracking and dashboards in React, Next.js or Angular.
APIs & databases
REST APIs in FastAPI or Node/Express, PostgreSQL or SQLite, login and roles, Docker deployment.
Admin consoles & dashboards
Internal tools to manage users, inventory, orders and reports, with live activity coming in from phones in the field. Built so non-technical staff can run the business from one screen.
ReactViteTailwindLive data
Utility apps, landing pages & games
Calculators, trackers, reminders, quote makers, landing pages and HTML5 browser games, with AdMob ads if you want the app to earn. Quick turnaround for focused, single-purpose projects.
Docs & handover
Technical documentation, architecture overviews and management decks.
Fixed-price or hourlyRemote, flexible hoursSource code & docs includedSupport after launch
Toolkit
Skills & stack
Languages 10
TypeScriptJavaScriptPythonC#JavaKotlinHTMLCSSSQLXAML
Mobile 11
React NativeExpoAndroid Studio.NET MAUINativeWindReanimatedPush notificationsAdMobAsyncStorageOffline-first syncAPK builds
Frontend 11
ReactNext.jsAngularViteTailwind CSSZustandReact RouterRechartsSVG chartsi18nAxios
Backend 7
FastAPINode.jsExpressREST APIsMicroservicesAPI gatewayAuth & roles
Data & DevOps 6
PostgreSQLSQLiteDockerDocker ComposeRenderGit
Tools & more 6
VS CodeVisual StudioFigmaPowerPointTechnical writingAI-assisted dev
Portfolio
Apps I've built
11 apps across Android, web and backend. Filter by type.
HO
Hybrid Ordering
A B2B ordering app for customers on the move. Place and manage orders, track deliveries, scan product barcodes, open order documents, or order through WhatsApp. Works in English, Indonesian and Chinese.
Expo appReact Native appExpress + SQLite API
ExpoReact NativeZustandi18nextNode.jsExpressSQLite
ORDERSPlace & manage orders
TRACKINGDelivery tracking
SCANBarcode product lookup
DOCUMENTSOrder documents
WHATSAPPOrder by chat
LANGUAGESEN · ID · ZH
MH
MasterHub
An admin dashboard to run a sales business from one screen: customers, orders, products and reports, plus an automation rules engine that handles routine order steps without manual work.
LoginDashboardRules engineReports
ReactReact RouterRechartsTailwind CSS
DASHBOARDKPIs at a glance
CUSTOMERSAccounts & details
ORDERSOrder management
PRODUCTSCatalogue
REPORTSSales charts
AUTOMATIONGeneric & custom rules
₹
EMI Calculator Pro
Loan EMI with a full repayment schedule, plus SIP, lump-sum, FD and GST calculators with donut-chart breakdowns.
ExpoSVG chartsAdMob
St
Streakly
Habit tracker with daily streaks, progress rings, an activity heatmap and rewards that keep you coming back.
ExpoReanimatedAdMob
Qc
QuoteCraft
Design quote images in an editor, then save them to the gallery or share them straight to social apps.
ExpoView ShotSharing
Cv
Convertly
Unit converter with a custom number keypad and a quick unit picker across common categories.
ExpoZustandAdMob
Aq
AquaDose
Water intake and medicine reminders with push notifications, an animated water orb and daily goals.
ExpoNotificationsAdMob
OD
Orders Dashboard
Orders dashboard app built once in C# and shipped to both Android and Windows.
.NET MAUIC#XAML
CP
B2B Customer Portal
Storefront with product catalogue, product pages, cart, sign-up and login, customer accounts and a protected admin area.
Angular 19TypeScriptRoute guards
Nw
News App
Business news reader pulling live headlines from news APIs into a fast, responsive layout.
ReactViteTailwindAxios
GH
GameHub
A browser gaming site featuring Cyber Assault, an original HTML5 game that runs in any browser.
JavaScriptHTML5CSS
Case studies
How I build real apps
A closer look at three projects: what each one had to do, what I built, and what was delivered.
HO
Hybrid Ordering
ExpoReact NativeZustandi18nextExpressSQLite
The goal
Give business customers one app to place orders, follow deliveries and find their order documents, in English, Indonesian or Chinese.
What I built
A mobile app with sign-in, home, orders, delivery tracking, barcode scanning, documents and ordering through WhatsApp. App state lives in Zustand, every screen is translated with i18next, and a Node.js + Express API with SQLite stores the data.
Delivered
- Two mobile builds from the same design: Expo and React Native CLI
- 7 app areas, from sign-in to WhatsApp ordering
- 3 languages: English, Indonesian, Chinese
- A REST API with its own database
MH
MasterHub
ReactReact RouterRechartsTailwind CSS
The goal
Run a sales business from one screen: customers, orders, products and reports, with routine order steps handled by rules instead of by hand.
What I built
A React single-page app with sign-in, a KPI dashboard, customer, order and product management, chart-based reports, settings, and a rules engine where staff create generic rules and automation rules.
Delivered
- 11 views, routed with React Router
- Sales charts built with Recharts
- A rules engine with generic and automation rules
- Responsive layout in Tailwind CSS
₹
EMI Calculator Pro
ExpoReact NativeSVG chartsAdMob
The goal
One simple Android app for everyday money maths: loan EMIs, investments and tax, with results people can understand at a glance.
What I built
An Expo app with an EMI calculator and full repayment schedule, plus SIP, lump-sum, FD and GST calculators. Results show as donut charts and growth summaries drawn in SVG, and a banner ad earns from free users.
Delivered
- 5 calculators plus a month-by-month repayment schedule
- Visual breakdowns with custom SVG donut charts
- Google AdMob monetization built in
- Packaged as an Android APK
Client reviews
What clients say
Be one of my first reviewers
If I've built something for you, I'd be grateful for a few words about it.
FAQ
Questions clients ask me
What kind of apps can you build?
Android and iOS apps with React Native, Expo or .NET MAUI; web apps, admin dashboards and customer portals with React, Next.js or Angular; and REST APIs with FastAPI or Node.js. The 11 apps above show the range.
How do you charge for a project?
Fixed price for clearly defined projects, or hourly for ongoing work. Send the form below with your idea and budget and I'll reply with a quote.
Do I get the source code?
Yes. You get the full source code and documentation when the project is delivered, so you own your app.
Can you work remotely with my team?
Yes. I work remotely with flexible hours and keep you updated as the work progresses.
Do you offer support after launch?
Yes. I stay available for fixes and updates after your app goes live.
Can you add ads or monetization to my app?
Yes. I've added Google AdMob ads to five of my own Android apps and can set them up in yours.
Hire me
Let's build your next app.
Tell me what you want to build, your timeline and budget. I reply with questions, a plan and a quote.
- You send the formA few lines about your idea is enough.
- I get back to youWith questions and a rough plan.
- We agree on a quoteFixed price or hourly, your choice.