RDRANAK DEBNATH
SERVICE 03 / MOBILE APP DEVELOPMENT

Need a React Native developer for your app?

I build iOS and Android apps in React Native and Expo, from the first screen to the store — with native Kotlin and CallKit modules where they matter, and the backend, payments and admin panel behind them.

STACKREACT NATIVE · EXPO · TYPESCRIPT · KOTLIN · CALLKIT · MAPBOX
FROMDHAKA · WORKING WORLDWIDE
PROTOTYPE — RANAK.BIO AS AN APP
01 / 06 — CLICK A CHAPTER TO JUMP

What if this portfolio were an app? A prototype for iOS and Android — projects, the Bravo Secure case study, a system map, the stack and AI work, redesigned for the phone.

WHAT YOU GET
01

One React Native and Expo codebase for iOS and Android, with native Kotlin and CallKit modules where the platform has to be reached directly.

02

Push notifications that reach a closed app — including calls that ring through CallKit on iOS and Telecom on Android.

03

Maps and live location: native Mapbox turn-by-turn navigation and real-time GPS tracking.

04

In-app payments and subscription plans with Stripe, credit wallets and region-based pricing.

05

Encrypted on-device storage with SQLCipher, MFA and secure file handling.

06

The backend, APIs and admin console the app needs — built by the same engineer, so nothing falls between two teams.

PROOF — SHIPPED IN PRODUCTION
03.1 / CASE STUDY

Bravo Secure

  • Encrypted messenger, bookings and live GPS missions for military personnel
  • Group calls scaled from 6 to 10 people; calls ring a closed app
  • ~1,430 tests added — coverage 51% → 74%
READ THE CASE STUDY
03.2 / CASE STUDY

Heritage Vault

  • Estate planning on mobile and web
  • Wills and power of attorney with digital signing
  • AES-256 encrypted document vault
READ THE CASE STUDY
HOW IT WORKS
01Tell me the ideaEmail or WhatsApp a few lines about what you want built. I usually reply within a day.
02Scope the first versionWe agree what the first release must do, the stack, and how we’ll know it works.
03Build with regular demosYou see working software early and often — not a big reveal at the end.
04Launch and keep goingIt ships, real users arrive, and we keep building on what they do.
QUESTIONS PEOPLE ASK

Do you build for both iOS and Android?

Yes. One React Native and Expo codebase ships to both, with native modules for the parts that need the platform directly — such as CallKit ringing on iOS and Telecom on Android.

Is React Native good for mobile app development?

For most products, yes: one codebase ships to iOS and Android, and native modules cover what it can’t — Bravo Secure’s CallKit call ringing and Mapbox turn-by-turn navigation run as native modules inside a React Native app.

Can you build the backend for my app too?

Yes. I build the NestJS backend, database, payments and admin console behind the app, so one engineer owns the whole system end to end.

Can you add maps, calling or payments to a mobile app?

Yes — I have shipped all three in production: native Mapbox navigation with live GPS, WebRTC group calls that ring a closed app, and Stripe payments with wallets and subscriptions.

Do you work with clients outside Bangladesh?

Yes. I work remotely with clients in the UAE, South Africa and the UK from Dhaka (GMT+6) — in English, with regular demos.

How do we start?

Email hello@ranak.bio or message me on WhatsApp with a few lines about the project. I usually reply within a day.

Tell me what to build.

hello@ranak.bioWHATSAPP