How to test an app built with AI on your phone

You described an app, and an AI built it. Maybe you used Claude or ChatGPT in a chat, Cursor or Windsurf in an editor, GitHub Copilot inside your code, or Gemini. Maybe you started in Lovable or Bolt and exported the project. Now you have a folder full of code, or a GitHub repository, and one big question: how do I test an app built with AI on my phone?

That is the moment many people get stuck. The chat says "run npx expo start" or "open it in Xcode", and suddenly you are reading about certificates, SDKs and USB debugging. Final Code skips all of that. It is a Mac app that opens your project, works out what kind of app it is, and runs it on real phones, simulators and emulators, with no terminal.

This page is for people who build with AI, whether you call it vibe coding, prompting or just "getting it done". It explains what Final Code does for you and how it helps your AI do a better job.

Why AI-written apps are hard to test

AI tools are very good at writing code. They are much worse at knowing whether that code actually works on a phone, because they cannot see one. A few things go wrong again and again:

• The AI never ran the app. It wrote code that looks right, but nobody pressed a button on a real screen.
• Libraries do not match. An AI may suggest a package version that does not fit the Expo or React Native version in your project.
• Release builds behave differently. Some code works while developing but crashes in the build your users download.
• Errors are hard to pass back. You copy half a red screen into the chat, the AI guesses, and the loop repeats.
• Setup is outside the code. A sign-in method switched off in Supabase or Firebase not set up looks like a bug, but no code change will fix it.

Final Code was built with exactly these problems in mind.

Run an AI-generated app on iPhone and Android in one window

Open your project folder or pick the repository from GitHub. Final Code detects the project type by itself: React Native, Expo (including Expo Router), Flutter, native Swift or Kotlin, Capacitor or Ionic, a web app built with React, Next.js, Vite, Vue or Svelte, or a game in Unity, three.js or React Native Filament. If the AI made a monorepo with several apps, Final Code finds each one and lets you switch in a click.

Then pick devices. An iPhone simulator and an Android emulator appear inside the Final Code window, and you can click, swipe and type on them. Plug in your own iPhone with a cable, unlock it and tap Trust, and Final Code signs and installs a real release build on it. Android phones connect by cable with USB debugging or over Wi-Fi with a pairing code. This is how you run an AI generated app on iPhone without learning Xcode.

The first native build takes a few minutes. After that, when the AI changes a file, every open simulator and emulator updates instantly.

Project check: catching AI mistakes before they crash

When your project opens, and every time new code arrives, Final Code runs a Project check. It looks for the mistakes AI tools commonly make: libraries that do not match the Expo version, React Native APIs that were removed in the version you have installed (these often crash only in release builds), missing babel plugins, files the app tries to load that do not exist, and worklets that use code declared further down the file. It also checks for missing tools on your Mac.

What is safe to fix, it fixes by itself. The rest gets one button and a plain sentence. If Final Code had to patch a library on your Mac, the "Store builds need a fix" button adds the same fix to your project with patch-package and pushes it, so builds made elsewhere (TestFlight, the App Store, EAS or Google Play) get it too.

Errors your AI can actually fix

The single most useful thing you can give an AI is a clear description of what went wrong. Final Code collects that for you.

Every error, crash, failed build and setup problem goes into the Issues box as one issue per problem, with how often it happened, on which device, the stack trace and the log lines just before. On real phones there is also a session log for each launch, with the app's JavaScript console, the phone's native output, the build and install steps, and crash reports with readable function names.

Then, in version 0.5.0, there is Share problem. One press builds a single report with:

• what happened,
• the exact file and line, with the code around it,
• what changed since the app last worked,
• the device and the Mac it happened on.

Passwords, keys and tokens are removed before anything leaves the panel. From there you choose:

• Explain this problem: Claude explains what went wrong in plain words, with steps to fix it.
• Copy for any AI tool: paste it into ChatGPT, Cursor, Copilot, Gemini, Windsurf or whatever you use.
• Copy as text, a private link that lasts 7 days, a GitHub issue, or a file.

Instead of "it is broken, please fix", your AI gets the full picture. That usually means a right answer on the first try, not the fifth.

And when the cause is not in your code at all, Final Code says so. A setup problem, such as a sign-in method switched off in Supabase or Firebase not set up, comes with a link to the right dashboard. That saves you from asking the AI to rewrite code that was never the problem.

The.finalcode bridge: let your AI test its own work

Copying reports is good. Letting the AI look for itself is better. Final Code writes a .finalcode folder inside your project. It holds the live status, logs, issues, screenshots and the build log, and it is never committed to git.

AI coding assistants that work in your project folder can read it. More than that, they can ask Final Code to build, run, reload, tap, swipe, type, take screenshots and read the phone log. In practice that means you can tell your assistant "add a settings screen and check it works on the iPhone", and it can build the change, open the screen on a real device, look at the screenshot and read the log to see if anything went wrong.

This closes the loop that makes AI coding frustrating. The AI is no longer guessing. It checks its own work on real devices, the same way a careful developer would.

Auto-sync from GitHub

Many AI tools work by pushing code to GitHub: a cloud agent, a coding assistant on another machine, or a teammate prompting from their laptop. Final Code checks GitHub every minute. When new commits arrive, it pulls them, rebuilds if native code changed, and every open device reloads.

So the workflow can be as simple as this: ask your AI for a change, let it push, and watch the phones on your desk update a minute later. If you edited something on your Mac in the meantime, your changes are kept or saved to a git stash. They are never lost.

Connecting GitHub takes one click and a short code you approve in your browser. There are no tokens to paste and no command-line tools to install. Use "Open from GitHub" to pick any repository and branch; Final Code picks the newest branch with app code automatically.

Lovable, Bolt and other exported projects

If you started in a browser-based builder and exported or synced the project to GitHub, Final Code treats it like any other project. A web app with a dev server opens in web screen shapes (iPhone, iPad, Android and foldable sizes), so you can check how it looks on a phone. If you wrapped it with Capacitor or turned it into a React Native or Expo app, Final Code runs it on simulators, emulators and real phones.

Vibe coding mobile app testing, step by step

1. Download Final Code and drag it to Applications.
2. Sign in with your email and a 6-digit code, and start the 14-day free trial in the app. No card needed.
3. Install what is missing. It finds what is on your Mac and installs the rest one click at a time.
4. Open your project from a folder, or connect GitHub and choose the repository your AI pushes to.
5. Pick an iPhone simulator, an Android emulator, and your own phone if it is plugged in. Press Run.
6. Use the app. When something breaks, open the issue and press Share problem, then Explain this problem or Copy for any AI tool.
7. Let your AI fix it and push. Final Code pulls the change and every device reloads. The issue shows "looks fixed" once the new code runs for 3 minutes without it.

For a deeper walk-through of every way to put an app on a phone, read our guide on how to test your app on iPhone and Android.

Private by design

Your code never leaves your Mac. Final Code has no analytics. Share problem strips secrets before you send anything, and you decide where every report goes. The only thing the app sends online for membership is your email, your plan and a one-way code for the Mac.

Who this is for

People who have never shipped an app and want to see their idea on a real phone tonight. Designers and founders who prototype with AI. Developers who use Copilot or Cursor all day and want their assistant to check its own work. Agencies that review AI-assisted code from several projects. If you build apps with AI and own a Mac, Final Code is the shortest path from "the AI says it is done" to "it works on my phone".

See every capability on the features page, check pricing, or ask us anything in support.