# Build a mobile app with an independent developer

> To build a mobile app, you describe the one job it does, choose between one shared codebase for iPhone and Android or two native apps, and split the work into small paid milestones. ErdiBuilds is an open marketplace where clients post app, SaaS, website and game projects, see which independent developers from the EU fit best based on what they have already built, and pay per milestone.

Canonical: https://erdibuilds.app/build/mobile-app
Last updated: 2026-11-06 (November 6, 2026)

## What a mobile app project looks like

A mobile app is software people install from the App Store or Google Play and use on their phone. It can send push notifications, use the camera, location or Bluetooth, and keep working with a weak connection. That is why people choose an app over a website for things they use every day.

Common examples are habit and fitness trackers, booking apps for a local business, companion apps for a physical product, community apps, delivery and field service apps, and learning apps. Games have their own page: see [mobile games](https://erdibuilds.app/build/mobile-game). If your product also needs a browser version, read about [a SaaS plus mobile app](https://erdibuilds.app/build/saas-plus-mobile-app).

> A good first version does one thing well. Every extra screen adds weeks and review time in the stores, so start with the moment people open the app for.

## Typical technologies

The biggest choice is between one codebase for both phones and separate native apps. Most first versions use one codebase, because it keeps the work smaller and updates quicker. [Find My Stack](https://findmystack.app/?project_type=mobile-app) can suggest a stack from your answers.

- React Native (A framework from Meta that builds iPhone and Android apps from one JavaScript or TypeScript codebase.) with Expo (A toolkit around React Native that handles builds, updates and store submission.) is a popular choice, especially for teams that also build websites.
- Flutter (A framework from Google that draws its own interface and builds iPhone and Android apps from one Dart codebase.) gives very consistent visuals on both platforms.
- Swift (Apple's programming language for native iPhone and iPad apps.) and Kotlin (A programming language for native Android apps, fully supported by Google.) suit apps that need deep device features or the newest platform functions.
- Supabase (An open source backend with a Postgres database, user login and file storage.) or Firebase (Google's backend service with a database, login and push messages.) often handle accounts and data, so no custom server is needed at the start.
- Push notifications (Short messages the app can send to a phone, even when the app is closed.) and in-app purchases (Payments for digital content or subscriptions that usually go through the store billing of Apple or Google.) need extra setup, so mention them early.

## An example plan in milestones

Every project differs, but a first version often follows this shape. Each milestone is funded before work starts and runs 1, 2, 3, 4, 6 or 8 weeks. Milestones are from 50 to 2,000 each in your project currency.

**Example phases for a first version of a mobile app**

|  | Example timing | What happens | What you can check |
| --- | --- | --- | --- |
| Phase 1: Design and setup | For example, weeks 1 to 2 | Screens for the main flow, project setup, test build on a real phone | Clickable screens and an app you can install for testing |
| Phase 2: Core flow | For example, weeks 3 to 6 | Sign in, the main feature, saving data, basic error handling | The core job works end to end on iPhone and Android |
| Phase 3: Extras | For example, weeks 7 to 8 | Push notifications, settings, empty states, analytics | A complete app for a closed test group |
| Phase 4: Store launch | For example, weeks 9 to 10 | Store listing, screenshots, privacy details, review and fixes | The app is live in the stores under your own accounts |

The weeks are for illustration. Developers set the length of each milestone in their proposal, and each real milestone runs 1, 2, 3, 4, 6 or 8 weeks, so a phase may be one milestone or several.

## What belongs in the project description

- The one job the app does and who uses it.
- Platforms: iPhone, Android or both, and the oldest versions you must support.
- The three to five screens that matter most. A sketch or a link to a similar app helps.
- Phone features you need: camera, location, notifications, offline use.
- Where data comes from: an existing system, a new backend or none.
- Who owns the store accounts. Using your own accounts keeps the app yours from day one.
- A preferred launch date and what can wait for version two.

[How to write a project brief](https://erdibuilds.app/guides/how-to-write-a-project-brief) walks through this in more detail, and the [project brief tool](https://erdibuilds.app/tools/project-brief) helps you draft one.

## How to recognise a suitable developer

Look for proof of finished apps: store links, a live demo or a repository you can read. Ask which apps they published, how they handled store review and what they would cut from your first version. Developers are independent professionals, not our employees.

ErdiBuilds also gives every proposal a match score (A number from 0 to 100 that shows how well a developer fits your project, with plain reasons such as shared technologies, similar past work, budget fit and availability.). A developer needs at least 40 to apply, and 80 or more earns a Top match badge. You see proposals sorted by score and can read why each one fits. Verified means an ErdiBuilds admin has reviewed the developer and approved the profile by hand.

For questions worth asking in a first chat, see [questions to ask before hiring a developer](https://erdibuilds.app/guides/questions-to-ask-before-hiring-a-developer).

## Frequently asked questions

### Should my app run on iPhone, Android or both?

Start where your first users are. If you are unsure, one shared codebase with React Native or Flutter lets you reach both. A developer can tell you if your features need a native app instead.

### Who publishes the app in the stores?

Your developer can do the upload, but the Apple and Google developer accounts should be yours. That way the listing and the app stay with you. Unless both sides agree otherwise in writing on the platform, the rights to the result of a milestone pass to the client once that milestone is paid in full.

### Can the stores reject my app?

Yes, reviews can ask for changes, for example on privacy texts or sign in. Plan a few days for it, and ask the developer to include review fixes in the last milestone.

### How do payments work?

Each milestone is funded before work starts and runs 1, 2, 3, 4, 6 or 8 weeks. You approve the delivery, and the funds are released after approval and a short holding period. If you do not respond, the milestone is approved automatically after 14 days.

### Can I add features after launch?

Yes. Many projects ship a small first version and add features in new milestones, with the same developer or a different one. Ask for readable code in your own repository so that stays easy.

## Related

- [Build a mobile game with a developer](https://erdibuilds.app/build/mobile-game): Plan a phone game: engines like Unity and Godot, a milestone plan from prototype to store release, what the brief needs and how to judge a developer.
- [Build a SaaS plus mobile app with a developer](https://erdibuilds.app/build/saas-plus-mobile-app): Plan a subscription product with a browser app and a phone app on one shared back end: technologies, milestone order, brief and developer fit.
- [Hire a React Native and Expo developer](https://erdibuilds.app/hire/react-native-expo): One codebase for iPhone and Android: what React Native and Expo can do, what to ask a developer, example milestones and how matching works.
- [Hire a Flutter developer for your app](https://erdibuilds.app/hire/flutter): Flutter builds iPhone and Android apps from one codebase. See what it suits, what to ask a Flutter developer and how a project is planned.
- [How Long Does It Take to Build an App?](https://erdibuilds.app/guides/how-long-does-it-take-to-build-an-app): What decides how long an app, SaaS, website or game takes to build, with an example plan in weeks and tips for planning realistic milestones.
- [Hire a Developer to Build Something New](https://erdibuilds.app/help/build-new): Turn an idea into a working product. See how to prepare, how milestones structure the work and what to ask developers before you start.