The instructions are a bit different depending on your development operating system, and whether you want to start developing for iOS or Android. If you
want to develop for both iOS and Android, that's fine - you just have to pick
one to start with, since the setup is a bit different.
<div>Unfortunately, Apple only lets you develop for iOS on a Mac. If you want to build an iOS app but you don't have a Mac yet, you can try starting with the <ahref=""onclick="display('platform', 'android')">Android</a> instructions instead.</div>
If you have already installed Node on your system, make sure it is version 4 or newer.
[Watchman](https://facebook.github.io/watchman) is a tool by Facebook for watching changes in the filesystem. It is highly recommended you install it for better performance.
Android Studio, which we will install next, requires a recent version of the [Java SE Development Kit (JDK)](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html) which can be installed using Chocolatey.
If you have already installed Node on your system, make sure it is version 4 or newer. If you already have a JDK on your system, make sure it is version 8 or newer.
The easiest way to install Xcode is via the [Mac App Store](https://itunes.apple.com/us/app/xcode/id497799835?mt=12). Installing Xcode will also install the iOS Simulator and all the necessary tools to build your iOS app.
If you have already installed Xcode on your system, make sure it is version 8 or higher.
You will also need to install the Xcode Command Line Tools. Open Xcode, then choose "Preferences..." from the Xcode menu. Go to the Locations panel and install the tools by selecting the most recent version in the Command Line Tools dropdown.
Setting up your development environment can be somewhat tedious if you're new to Android development. If you're already familiar with Android development, there are a few things you may need to configure. In either case, please make sure to carefully follow the next few steps.
> Android Studio requires a recent version of the [Java SE Development Kit (JDK)](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html). Go ahead and install JDK 8 or newer if needed.
Android Studio provides the Android SDK and AVD (emulator) required to run and test your React Native apps. [Download Android Studio](https://developer.android.com/studio/index.html), then follow the [installation instructions](https://developer.android.com/studio/install.html). Choose `Custom` installation when prompted by the Setup Wizard, and proceed to the next step.
Android Virtual Devices allow you to run Android apps on your computer without the need for an actual Android phone or tablet. Choose `Custom` installation when running Android Studio for the first time. Make sure the boxes next to all of the following are checked:
> If you've already installed Android Studio before, you can still [install HAXM](https://software.intel.com/en-us/android/articles/installation-instructions-for-intel-hardware-accelerated-execution-manager-windows) without performing a custom installation.
Android Virtual Devices allow you to run Android apps on your computer without the need for an actual Android phone or tablet. Choose `Custom` installation when running Android Studio for the first time. Make sure the boxes next to all of the following are checked:
Click "Next" to install all of these components, then [configure VM acceleration](https://developer.android.com/studio/run/emulator-acceleration.html#vm-linux) on your system.
Android Studio installs the most recent Android SDK by default. React Native, however, requires the `Android 6.0 (Marshmallow)` SDK. To install it, launch the SDK Manager, click on "Configure" > "SDK Manager" in the "Welcome to Android Studio" screen.
> The SDK Manager can also be found within the Android Studio "Preferences" menu, under **Appearance & Behavior** → **System Settings** → **Android SDK**.
Select the "SDK Platforms" tab from within the SDK Manager, then check the box next to "Show Package Details" in the bottom right corner. Look for and expand the `Android 6.0 (Marshmallow)` entry, then make sure the following items are all checked:
Next, select the "SDK Tools" tab and check the box next to "Show Package Details" here as well. Look for and expand the "Android SDK Build Tools" entry, then make sure that `Android SDK Build-Tools 23.0.1` is selected.
> Please make sure you export the correct path for `ANDROID_HOME`. If you installed the Android SDK using Homebrew, it would be located at `/usr/local/opt/android-sdk`.
Follow the [Watchman installation guide](https://facebook.github.io/watchman/docs/install.html#build-install) to compile and install Watchman from source.
> [Watchman](https://facebook.github.io/watchman/docs/install.html) is a tool by Facebook for watching
changes in the filesystem. It is highly recommended you install it for better performance, but it's alright to skip this if you find the process to be tedious.
Once in the "AVD Manager", select your AVD and click "Edit...". Choose "Android 6.0 - API Level 23" under Device, and "Intel Atom (x86_64)" under CPU/ABI. Click OK, then select your new AVD and click "Start...", and finally, "Launch".
> It is very common to run into an issue where Android Studio fails to create a default AVD. You may follow the [Android Studio User Guide](https://developer.android.com/studio/run/managing-avds.html) to create a new AVD manually if needed.
### Using a real device
If you have a physical Android device, you can use it for development in place of an AVD. Plug it in to your computer using a USB cable and [enable USB debugging](https://developer.android.com/training/basics/firstapp/running-app.html) before proceeding to the next step.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-ios` inside the newly created folder.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-android` inside the newly created folder:
`react-native run-android` is just one way to run your app - you can also run it directly from within Android Studio or [Nuclide](https://nuclide.io/).
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native start` inside the newly created folder to start the packager.
Use the React Native command line interface to generate a new React Native project called "AwesomeProject", then run `react-native run-android` inside the newly created folder.
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
- If you can't get this to work, see the [Troubleshooting](docs/troubleshooting.html#content) page.
- If you're curious to learn more about React Native, continue on
- If you want to add this new React Native code to an existing application, check out the [Integration guide](docs/integration-with-existing-apps.html).
