Add `RNI18n.xcodeproj` to **Libraries** and add `libRNI18n.a` to **Link Binary With Libraries** under **Build Phases**. [More info and screenshots about how to do this is available in the React Native documentation](http://facebook.github.io/react-native/docs/linking-libraries-ios.html#content).
Add `react-native-i18n` to your `./android/settings.gradle` file as follows:
```
include ':app', ':react-native-i18n'
project(':react-native-i18n').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-i18n/android')
```
Include it as dependency in `./android/app/build.gradle` file:
```
dependencies {
...
compile project(':react-native-i18n')
}
```
Finally, you need to add the package within the `ReactInstanceManager` of your MainActivity (`./android/app/src/main/java/your/bundle/MainActivity.java`):
When fallbacks are enabled (which is generally recommended), `i18n.js` will try to look up translations in the following order (for a device with `en_US` locale):
- en-US
- en
**Note**: iOS locales use underscored (`en_US`) but `i18n.js` locales are dasherized (`en-US`). This conversion is done automatically for you.
```js
I18n.fallbacks = true;
I18n.translations = {
'en': {
greeting: 'Hi!'
},
'en-GB': {
greeting: 'Hi from the UK!'
}
}
```
For a device with a `en_GB` locale this will return `Hi from the UK!'`, for a device with a `en_US` locale it will return `Hi!`.