Mobile App Development

React Native apps shipped fast, built to scale.

iOS and Android from a single codebase. MVP development for funded startups — App Store submission, push notifications, auth, and payments.

Book Free App Consultation →See Our Work ↓

No commitment. Response within 24 hours. Clients in USA, UK & Australia.

React Native Specialists
TOP RATED
Average MVP-to-Launch Timeline
8wks
Scope to App Store submission
1 codebase
Cross-Platform
iOS + Android simultaneously
48hr
Fixed-Price Quotes
Written scope, no surprises
10+ yrs
Experience
Upwork Top Rated, verified

React Native · iOS · Android

✓ App Store & Play Store — 10+ yrs verified

Trusted onUpwork — Top Rated · 10 YearsReact Native SpecialistsiOS & Android Experts50+ Apps ShippedClutch — Verified
The Problem

Why Most Mobile App Projects Fail Before They Ship

You Got a Demo, Not a Product

You hired a development shop and 6 months later, you have a demo — not a product. Most mobile app development companies separate design, development, and QA into different teams, different timelines, and different invoices.

The Quote Was Never the Final Price

The quote looked reasonable. Then came the change requests, the platform-specific rewrites, and the maintenance charges. Building native iOS and Android separately doubles your cost — and your headaches.

8 Months of Process. Zero Product.

You're a founder. You need a working MVP in 8 weeks, not a project plan that runs for 8 months. Offshore agencies take your brief, then disappear into a process you can't see or steer.

The App Launched. Nobody Noticed.

You built the app. Nobody downloaded it. Most app making companies stop at launch. Nobody told you about ASO, performance marketing, or what happens after you hit "publish" on the App Store.

What We Build

Full-Cycle Mobile App Development Services

01

React Native Cross-Platform Apps

One codebase. iOS and Android. React Native cross-platform mobile app development services that cut your build time by 40% without compromising on performance or user experience.

Cross-PlatformReact Native
02

iOS App Development

Native and React Native iOS app development services — built for App Store approval, smooth performance, and the standards your US and UK users expect from day one.

iOSSwiftReact Native
03

Android App Development

Android app development built for real-world conditions — fragmented devices, OS versions, and the Google Play standards that separate approved apps from rejected ones.

AndroidKotlinReact Native
04

MVP Development for Startups

Funded startup with a deadline? We build testable MVPs in 6–10 weeks — a working product investors can see and early users can stress-test. Scope-locked. Timeline-committed. No surprises.

MVPStartups6–10 Weeks
05

App Maintenance & Scaling

Your app shipped. Now what? OS updates, performance optimisation, feature additions, and scaling infrastructure — so your product doesn't decay the moment it's live.

MaintenanceScalingSupport
06

UI/UX Design for Mobile

Design is conversion. Every screen we design follows mobile UX best practices for App Store ratings, session depth, and user retention. Prototypes before a single line of code.

UI/UXFigmaPrototype
The Process

From Idea to App Store. Here's Exactly How We Work.

01

Discovery & Scoping

We start with a free consultation call to map your idea, your users, and your constraints. Within 48 hours, you get a scope document: features, tech stack, timeline, and fixed price. No surprises.

02

Build & Iterate

Development starts in week 1. You get a working build every 2 weeks — not a progress report. You test on real devices, give real feedback, and we ship real updates. Our AI-augmented development workflow ships 3× faster than traditional agency timelines.

03

Launch & Beyond

We handle App Store and Google Play submission, rejection resolution, and launch-day monitoring. Post-launch, we're your ongoing development partner — not a vendor who disappears after the invoice.

Technology

Our Mobile App Technology Stack

Cross-Platform
React Native · Expo
iOS Native
Swift · SwiftUI
Android Native
Kotlin · Jetpack Compose
Backend / API
Node.js · Python · REST · GraphQL
Database
Firebase · PostgreSQL · Supabase
Auth
Auth0 · Firebase Auth · Supabase Auth
Push Notifications
Firebase Cloud Messaging · OneSignal
Analytics
Mixpanel · Amplitude · Firebase Analytics
Payments
Stripe · RevenueCat
Cloud
AWS · Google Cloud · Vercel
DevOps
GitHub Actions CI/CD · Fastlane

We default to React Native for most projects — one codebase, 90%+ of native performance, deployed to both App Store and Google Play simultaneously. When a client genuinely needs platform-specific capabilities, we build native. We tell you which before a single line of code is written.

The BillionX Difference

Why Funded Startups Choose BillionX Over Local Agencies

3× Faster Delivery

Our AI-augmented development workflow — Claude Code + a full AI toolchain — means your MVP ships in weeks, not months. We've built production-ready React Native apps in under 8 weeks. Verifiable on request.

Dev + Growth Under One Roof

Most mobile app development agencies hand you an app and leave. BillionX combines development with performance marketing, ASO, and conversion rate optimisation — so your app doesn't just exist, it grows.

You Work With Dushyant Directly

Not account managers. Not offshore sub-teams you never meet. Dushyant leads every project personally — 10+ years on Upwork, 50+ apps shipped. Your brief goes to the person building it.

60% Lower Cost. Same US/UK Standards.

India-based means your budget stretches further without quality compromise. We're Upwork Top Rated with a 10-year verified track record serving clients in the USA, UK, and Australia. The best mobile app development agency in India for Western market standards.

Proof

Numbers That Aren't Made Up

0+
Years on Upwork
Top Rated since 2014
0+
Projects Shipped
Mobile, web & eCommerce
8wks
Avg MVP to App Store
Scope to submission
4
Markets Served
USA · UK · Europe · AU
Client Win — eCommerce, USA

App + Ads + CRO. One Sprint. $300K+. 60 Days.

We built the Shopify eCommerce platform, ran Meta Ads, and managed CRO simultaneously — for a single client, in a single sprint. ROAS went from 1.8x to 8x. $300K+ in revenue generated within 60 days of launch. That's what full-funnel delivery looks like.

8x
ROAS Achieved
Was 1.8x
$300K+
Revenue Generated
In 60 days
4
Services Combined
One team, one roof
1
Integrated Team
Dev + Ads + CRO
See Full Case Study →
Who We Work With

Built for Founders and Growth Teams Who Ship, Not Pitch

Funded Startups

You have a round and a roadmap. You need a mobile app that investors can see in Q1 and users can stress-test in Q2. We build validated MVPs on fixed scopes — no scope creep, no moving goalposts.

Scaling Businesses

Your web product works. Now your customers want mobile. We build the iOS and Android extension of your existing business — connected to your CRM, your auth system, and your backend from day one.

We also build the web backend

Agencies (White Label)

Your client needs a mobile app. You don't have a mobile team. We deliver under your brand — design, development, testing, and launch. You invoice. Your client never needs to know.

See our white-label services
Frequently Asked

Mobile App Development Questions Answered

A mobile app development agency is a company that designs, builds, and launches mobile applications for iOS, Android, or both platforms. Services typically include UI/UX design, front-end development, backend API integration, App Store submission, and ongoing maintenance. A full-service agency like BillionX Software also handles post-launch growth — including performance marketing and app store optimisation.

LET'S BUILD

Your Mobile App Starts With One Call.

Book a free 30-minute consultation. We'll review your idea, tell you what's possible in your timeline and budget, and give you a written scope within 48 hours. No commitment required.

Book Free App Consultation →

Clients in USA · UK · Australia · Europe · No commitment · Response within 24 hours