Building a mobile app

A Playcode Cloud project can include a real iPhone and Android app, built from the same project as your website and wired to the same backend. You ask for it in chat, watch it in the Phone tab, and open it on your own phone with a QR code. Builds for the stores run in the cloud, so no Mac is required.

What you get

A Cloud project holds your website, your backend, and a mobile app side by side. The app is built with React Native and Expo, the same tools professional mobile teams use, and one codebase becomes both the iPhone app and the Android app.

• One backend for both. Accounts, database, and business rules live in the project's backend and are shared with the website. Someone who signs up on your site signs in on the phone.
• Sign-in already wired. A new project's app arrives with sign-in, sign-up, and a settings screen connected to your own backend, not a mockup.
• Nothing to install on your computer. The app is built and run on your project's machine in the cloud.

Cloud projects created since the mobile app shipped already contain the app folder. Older projects do not - see If your project has no mobile app yet below.

How to ask for it

Ask in chat, in plain words: show it on my phone, or add a mobile app. The agent edits the app and starts the phone preview for you.

The preview is off until someone asks for it, because it uses real memory on your project's machine. Ask the agent to stop it when you are done with mobile work, and ask again next time. It only ever runs on your project's development machine - it never touches a published app.

Where the phone preview lives: the Phone tab

On a computer, the Phone tab opens by itself, beside Preview, as soon as the preview is ready. To open or close it yourself, open the project menu (the project name in the top left corner), then View, then Phone. When you are working from a phone, the same Phone row is in that menu.

The tab holds the app and the ways into it:

• The app running inside a phone frame, so you see it the way a phone does.
• A QR code to point your phone's camera at.
• The preview address, with a button that copies it.
• A Browser / Expo Go switch that decides what the QR code and the address point to.
• One line of state: Running, Starting, or Not running, plus a button that reloads the preview.

When you open the tab on a phone, there is no QR code - a phone cannot scan itself - and an Open on this phone button takes its place.

Opening the app on your own phone

The browser (the default)

Leave the switch on Browser and point your phone's camera at the QR code. The app opens in the phone's browser. There is nothing to install and no account to create. This is the same render you see in the phone frame in the editor.

Expo Go (the native app)

Set the switch to Expo Go and the QR code opens the app in Expo Go, the free preview app from Expo. This runs the app natively rather than in a browser.

• On iPhone, the accounts have to match. Expo now opens a project only when Expo Go on the phone and your project are signed in to the same Expo account. Ask in chat and the agent walks you through it.
• Expo Go runs one Expo version at a time. Playcode checks your project against the Expo Go currently on the App Store before it hands you a QR code, and updates the project first when the two do not match.
• Some libraries cannot run in a preview. Expo Go only carries the native pieces it was built with, so a library with its own native code will not load there.
• You scan once. Expo Go keeps the app in its list, so coming back is a tap.

What takes time

• Starting the preview. On a machine that has not run it before, the first start takes a minute or two.
• The first screen. The first bundle takes about 15 seconds. After that, edits you ask for reload on the phone while you watch.
• A store build. A build for the App Store or Google Play is not a live reload. The agent has to build the app in the cloud and upload it again, and store review takes days.

The preview address and your machine

The phone preview runs on your project's development machine, at its own address. Anyone you give that address to can use the app while the machine is on - your phone, a teammate, a client on a call.

It is not a public link, and it is not your published site. Only you turn the machine on, by opening the project in Playcode, and so does the agent while it works for you. The machine sleeps after a quiet while, and after four hours without you or the agent. While the app is being used on a phone, the machine stays awake.

When the machine is asleep, the app on your phone shows a banner with one button that opens the project in Playcode and wakes it. Nothing the phone sends can wake the machine on its own. The Phone tab says the same thing and offers a Wake it up button.

Publishing is the permanent address. A published Cloud app lives on playcode.run and works for everyone whether your development machine is awake or not. Publishing serves your website - your mobile app reaches people through the stores, as an installed app.

Putting it in the App Store and Google Play

Store builds run in Expo's cloud build service, so nothing in the process needs a Mac on your desk. The agent can drive it from your project: set up the build, run it, upload the result to App Store Connect or Google Play, draft the description, keywords and privacy answers, and take screenshots from the running app.

What is yours to do:

1. Open the developer accounts. You need your own Apple and Google developer accounts. Both charge a yearly fee and enrolment is not instant: identity checks, two-factor, and tax and banking forms. Check their current prices and requirements before you plan a launch, and start early.
2. Review the draft listing. Read every line the agent wrote and correct what is wrong.
3. Press submit. The final submit happens in your own account.

The app is published under your own developer account, never under Playcode's. Apple requires the owner of the content to hold the account, and it is what you want anyway - the app is yours.

What Playcode does not do

• It does not submit the app for you. Playcode builds it, uploads it, and drafts the listing. The last click is yours, in your own account.
• It cannot promise approval. No builder can. Review takes days and can bounce. The durable rule is that an app which only repackages a website gets refused, so give yours at least one job that needs the phone.
• It does not open your store accounts. Account creation, two-factor, and the tax and banking forms are yours, and the developer fees go to Apple and Google, not to Playcode.
• It does not run the phone preview on a published app. The preview is a development tool on your own machine.

If your project has no mobile app yet

Projects created before the mobile app shipped do not have one. Ask for it in chat. The agent checks the project, adds the app pinned to the Expo version that Expo Go runs today, and wires it to your project's own backend. Your existing accounts and data keep working - the app uses the backend you already have.

Where to go next

• A mobile app needs a Cloud project, and Cloud apps are part of the paid plans. See Pricing for the current limits.
• AI Mobile App Builder walks through what a mobile app on Playcode ships with, and what a store launch asks of you.
• How to publish a website covers the other half of a project: putting your site live.