Build a mobile app for iPhone and Android

A mobile app is a real app for iPhone and Android phones, not a website in a frame. Crisp builds it with Expo and React Native, the tools many popular apps use, and gives it its own backend: the part that stores the data, signs people in and keeps your keys safe. The backend runs on Crisp, like every Crisp app.

Start a mobile app#

1. 1 On your dashboard, choose Mobile app under the box where you describe your app.
2. 2 Describe the app, for example who uses it and what they do on each screen, and choose Build it.
3. 3 Crisp plans the screens, the tabs and the data, then builds them while you watch.

You cannot switch a project between a web app and a mobile app later. Start a new project instead.

See it in the preview#

The preview shows your app in a phone frame. It is the web version of your phone app, so you can tap through it right away. It updates as Crisp changes the code.

Open it on your phone#

1. 1 Install Expo Go from the App Store or Google Play. It is free.
2. 2 In the preview, look at Open it on your phone (on a narrow screen, choose On your phone).
3. 3 Scan the QR code: with the camera on an iPhone, or from Expo Go on Android. Your app opens in Expo Go and updates as Crisp builds it.

On an iPhone, Expo Go only opens apps from your own Expo account. Connect Expo in the App stores panel (below) and sign in to Expo Go with the same account. Android phones do not need this.

Publish to the App Store and Google Play#

Crisp builds your app on Expo's build service (EAS) with your own developer accounts, so the app is yours in both stores. Open the More menu in the top bar of your project and choose App stores. The panel walks you through each step and shows each build as it goes.

1. 1 Publish your app first. Store builds talk to its permanent address, so later changes to the backend reach every phone without a new build.
2. 2 Connect Expo: create a free account at expo.dev, create an access token under Account settings, then Access tokens, and paste it.
3. 3 Name your app and pick its ids, like com.yourname.plants. They cannot change after the first upload to a store.
4. 4 Android: choose Build a file to install to get an APK you can open on any Android phone, or Build for Google Play for the store.
5. 5 iPhone: add your App Store Connect key, then choose Build for the App Store.
6. 6 When a build is ready, download it, or choose Send to TestFlight or Send to Google Play.

The first time on Google Play

• Create the app in the Play Console with the package name you picked.
• Upload the first Google Play build by hand to Internal testing. Google requires this once; after that, Crisp sends builds for you.
• Create a service account with access to your app, download its JSON key, and paste it in the App stores panel.
• New personal Play accounts must run a closed test with 12 testers for 14 days before the app can go public.

The first time on the App Store

• In App Store Connect, under Users and Access, then Integrations, create a Team key with the Admin role. Download the .p8 file (Apple offers it once) and paste it with its key ID, the issuer ID and your team ID.
• Create the app in App Store Connect with the bundle ID you picked, and paste its Apple ID (a number under App Information) in the panel.
• Builds go to TestFlight. Test them on your phone, then send one to App Review from App Store Connect.

Your keys stay yours#

Your Expo token, App Store Connect key and Google Play key are stored encrypted. They are used only to build and send your app. The AI that builds your app never sees them, and they are never put in your app.

What is not done for you#

• Store listings: the description, screenshots, privacy details and age rating are filled in on App Store Connect and the Play Console.
• Sending an app to review, and answering the reviewers.
• Payments for digital goods inside an iPhone app must use Apple's in-app purchase, which Crisp does not set up yet. Payments for real-world goods and services can use Stripe.