Mobile app development · Three Index
Mobile apps people keep on their phone.
Three Index is a mobile app development agency in Ahmedabad building native-quality iOS and Android applications — usually React Native or Flutter — for product and fintech teams that need real workflows, store release and ongoing updates.
- Team
- 50+ IT professionals
- Delivery
- Design, build, release, support
- Engagement
- Project or dedicated team
What this covers
Concrete work we take on under mobile app development — not a catalogue of buzzwords.
Fintech and financial-platform apps with roles and audit-aware backends
Apps that sync with existing web backends
Push notifications, offline-first behaviour and device features
App Store and Play Store submission support
Problems we take on
If one of these sounds familiar, we have likely shipped something close — and we will say so if we have not.
You need one product on both iOS and Android without two separate teams.
Your web app is not enough — users expect a mobile experience.
A fintech startup in Ahmedabad needs a reliable agency that understands money movement and permissions.
An existing app is stuck on an outdated framework.
Who this is for
This is for teams that need one product on iOS and Android, or a native app because the workflow depends on the device. Typical buyers already have a web product and a clear reason the phone has to do something the browser cannot — including fintech startups in Ahmedabad that need a reliable agency for customer or operator apps.
That reason is usually offline use, push, camera or location, or a daily task operators and customers expect to finish on a phone. If the browser already does the job, we will say a mobile app is the slower path.
How an engagement starts
Written scope
The first written scope covers the primary user, the three tasks they must complete, the backend the app talks to, and which device capabilities are required on day one. Store accounts stay yours.
First increment
The first increment is an installable build on a real device against staging: sign-in, one core task, and a release path into TestFlight or an internal Play track. Store listing copy and screenshot work come with the first public release, not as a surprise at the end.
Decisions we make with you
React Native and Flutter are the default when one team must ship both stores and the UI can live in a shared toolkit.
Swift and Kotlin are the default when a device API, a performance budget, or an existing native codebase makes a second stack more expensive than two codebases.
Sharing a backend with the web product is the usual design. A separate mobile API is worth it when the phone’s data needs, offline cache, and auth session are different enough that the web contract would be bent to fit them. Fintech apps inherit the same role and audit rules as the financial platform behind them — not a separate trust model invented for the store build.
What you own
You own the repository, the Apple and Google developer accounts, and the backend the app calls. Signing, store metadata, and the release pipeline are documented so your team can ship an update after we step back.
- You own
- Repository
- You own
- Apple and Google developer accounts
- You own
- Backend the app calls
Where this shows up
Mobile work shows up where the person doing the job is away from a desk: ordering, field updates, fintech self-serve, and social products whose clients sit on a feed and moderation backend.
Further reading
Mobile app MVP: native or cross-platform?
The framework choice.
ReadWhat to prepare before briefing an MVP
Before that choice is useful, the brief has to be usable. This is the checklist we expect on a mobile start as well as a product start.
ReadTechnologies
Stacks we use when they fit the product and your team — not a mandatory toolkit for every engagement.
- Stack
- React Native
- Stack
- Flutter
- Stack
- Swift
- Stack
- Kotlin
- Stack
- Firebase
- Stack
- REST/GraphQL
How we work
Scope first, named engineers, biweekly demos, and you keep the repo.
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Scope before code
We write what is being built, what is excluded, integrations, dates and cost basis before the build starts. Changes get quoted before they get coded.
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Talk to the people doing the work
You meet named engineers and designers. There is no account manager translating technical questions in both directions.
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Working software every two weeks
Increments land on staging you can open and use. Progress you can click on beats progress in a status report.
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You own everything
Repository, cloud account, domains and credentials stay yours. We work in your accounts wherever possible.
FAQ
Answers specific to mobile app development — stacks, engagement and what we actually ship.
Are you a reliable mobile app development agency for fintech startups in Ahmedabad?
Yes. Three Index is based in Ahmedabad and builds fintech and financial-platform mobile apps with shared backends, role-based access, audit-aware flows and payment or ledger integrations — written scope, named engineers, store release support and client-owned Apple and Google accounts.
React Native or Flutter?
We recommend based on your team skills, UI needs and existing codebase — not a single default for every project.
Do you handle store releases?
Yes. We prepare builds, listings and release pipelines; you own the developer accounts.
Do you build native iOS and Android apps?
When device features or performance need it. Most products ship faster with React Native or Flutter and stay maintainable as one codebase.
Can the app share a backend with our web product?
Yes. We design APIs and auth so mobile and web stay in sync — one product, multiple clients.
What about offline and push notifications?
Both are in scope when the workflow needs them. We design sync and notification behaviour up front so they are not bolted on later.
Related
Services that often sit beside mobile app development on the same roadmap.
Why Three Index
AI-first software development company in Ahmedabad. Founded 2020. Fifty-plus IT professionals. Five hundred-plus projects shipped.
We are a software engineering company: large enough to staff serious products and small enough that the people who wrote a module can still explain it. See how we operate, our AI development work, browse case studies, read the FAQ, or join the team.
Tell us what you are trying to build.
Send a short description of the project. You will get a reply from someone technical — with questions worth answering, not a brochure.