# Run on iOS Simulator with Expo Go

## Set up an iOS Simulator with Expo Go
## Set up Xcode
<XcodeInstructions />
## Install Expo Go
When you start a development server with `npx expo start` on the [start developing](/get-started/start-developing) page, press <kbd>i</kbd> to open the iOS Simulator. Expo CLI will install Expo Go automatically.



## Next step
You have a project and a development environment. Now it's time to start developing.


## Start developing

Make your first change to an Expo project and see it live on your device.

Step 1: 
## Start a development server
To start the development server, run the following command:
```sh
$ npx expo start
```
Step 2: 
## Open the app on your device
After running the command above, you will see a QR code in your terminal. Scan this QR code to open the app on your device.
If you're using an Android Emulator or iOS Simulator, you can press <kbd>a</kbd> or <kbd>i</kbd> respectively to open the app.
Note: Having problems?
---
Make sure you are on the same Wi-Fi network on your computer and your device.
If it still doesn't work, it may be due to the router configuration &mdash; this is common for public networks. You can work around this by choosing the **Tunnel** connection type when starting the development server, then scanning the QR code again.
```sh
$ npx expo start --tunnel
```
> Using the **Tunnel** connection type will make the app reloads considerably slower than on **LAN** or **Local**, so it's best to avoid tunnel when possible. You may want to install and use an emulator or simulator to speed up development if **Tunnel** is required to access your machine from another device on your network.
---
Step 3: 
## Make your first change
Open the **app/(tabs)/index.tsx** file in your code editor and make a change.
```diff
diff --git a/app/(tabs)/index.tsx b/app/(tabs)/index.tsx
index 45cfa0e..4d1b384 100644
--- a/app/(tabs)/index.tsx
+++ b/app/(tabs)/index.tsx
@@ -17,7 +17,7 @@ export default function HomeScreen() {
      }
    >
      <ThemedView style={styles.titleContainer}>
-       <ThemedText type="title">Welcome!</ThemedText>
+       <ThemedText type="title">Hello World!</ThemedText>
        <HelloWave />
      </ThemedView>
      <ThemedView style={styles.stepContainer}>
```
Note: Changes not showing up on your device?
---
Expo Go is configured by default to automatically reload the app whenever a file is changed, but let's make sure to go over the steps to enable it in case somehow things aren't working.
- Make sure you have the [development mode enabled in Expo CLI](/workflow/development-mode#development-mode).
- Close the Expo app and reopen it.
- Once the app is open again, shake your device to reveal the developer menu. If you are using an emulator, press <kbd>Ctrl</kbd> + <kbd>M</kbd> for Android or <kbd>Cmd â</kbd> + <kbd>D</kbd> for iOS.
- If you see **Enable Fast Refresh**, press it. If you see **Disable Fast Refresh**, dismiss the developer menu. Now try making another change.
---
---
## File structure
Below, you can get familiar with the default project's file structure:
<ProjectStructure />
## Features
The default project template has the following features:
<TemplateFeatures />


## Next steps

Develop, review, and submit your project.

Here are next steps to continue building your app:
### Reset your project
You can remove the boilerplate code and start fresh with a new project. Run the following command to reset your project:
```sh
$ npm run reset-project
```
This command will move the existing files in **app** to **app-example**, then create a new **app** directory with a new **index.tsx** file.
### Develop, review, and deploy
Learn how to develop by reading the docs in the Develop section. You'll learn how to create [UI elements](/develop/user-interface/splash-screen-and-app-icon/), add [unit tests](/develop/unit-testing/), include [native modules](/config-plugins/introduction/), and more.
Once you've developed your app, you can share it with your teammates for [review](/review/overview).
Finally, you can [build](/deploy/build-project/) and [submit](/deploy/submit-to-app-stores/) your project to the app stores.
### Step-by-step guide
For a guided, step-by-step walkthrough of building an app with Expo from start to finish, check out the [tutorial](/tutorial/introduction/).