Step by step: your to-do app, built with AI and shipped to Android and iOS

This is a complete guide, from zero: we build a to-do app with an AI agent, watch it change live, open it on a phone and finally turn it into installable Android and iOS apps using your own Expo account. You write no code at all.

Step 1: the box and the agent

You need an AgentBox (any plan with 4 GB or more) and a subscription or API key for an agent, for example Claude Code. If you do not have the box yet, the getting-started guide takes you from order to first prompt in 15 minutes. In the terminal you run claude and sign in with your own account.

Step 2: install Mobile apps

On the AgentBox tab, under Apps, click Mobile apps. The install takes a few minutes: the box gets Node, Expo and a starter project, and three new views appear in the layout bar, among them Terminal + App. Pick that one: terminal on the left, your app on the right at phone size.

Step 3: ask for the app

In the terminal, tell the agent something like:

In the existing Expo project, build a to-do app: I add tasks, tick them off, delete them, and the list is saved locally on the phone. Clean design, dark mode. After every batch of changes run agentbox-expo reload.

That last sentence matters: the agent already knows from the box's instructions to reload the preview, but asking explicitly helps in the first session. Within minutes the first version shows in the App pane, and every change lands in seconds. React to what you see: bigger button, finished tasks at the bottom, add a counter.

Step 4: the app on your own phone

Install Expo Go from the App Store or Google Play, then scan the QR code shown in the App pane. Your app opens on the phone, connected to the box: every change the agent makes appears there too. At this point you already have an app you can use daily, with no extra accounts.

Step 5: the Expo account and installable builds

For standalone apps that run without Expo Go, you use EAS, Expo's build service. Create a free account on expo.dev, then tell the agent:

Log in to EAS with my account and configure the project for builds.

The agent runs npx eas-cli login (a takeover moment: you type your own password through the live desktop) and eas build:configure. Builds run on Expo's servers under your account, not on the AgentBox, so the plan size does not matter.

Step 6: Android

Make an Android build I can install directly. The agent runs eas build -p android --profile preview, and the result is an .apk with a link and a QR code: open it on your phone and install the app directly. For Google Play you ask for the production profile, which produces an .aab to upload in the Play console (Google developer account, one-time 25 USD fee).

Step 7: iOS

Apple requires the Apple Developer Program (99 USD per year). With it, the agent runs eas build -p ios and EAS handles certificates and profiles. The app reaches you through TestFlight, and from there, once you are happy, eas submit -p ios sends it to the App Store. Without an Apple account, the phone version stays available through Expo Go, which for personal use is often enough.

What you end up with

• A to-do app built entirely by vibe coding, with the code on your own box.
• The live version on your phone through Expo Go, updated on every change.
• An installable .apk for Android and, with an Apple account, the iOS build through TestFlight.

The same flow works for any mobile app, not just to-do. See also the mobile apps with AI tutorial and the vibe coding introduction.