$ npm install react-native-home-pressed --save

$ react-native link react-native-home-pressed

1. Open up android/app/src/main/java/[...]/MainActivity.java

• Add import com.evanjmg.RNHomePressedPackage; to the imports at the top of the file
• Add new RNHomePressedPackage() to the list returned by the getPackages() method

2. Append the following lines to android/settings.gradle:

   include ':react-native-home-pressed'
   project(':react-native-home-pressed').projectDir = new File(rootProject.projectDir,   '../node_modules/react-native-home-pressed/android')
   

3. Insert the following lines inside the dependencies block in android/app/build.gradle:

     compile project(':react-native-home-pressed')
   

• 'ON_HOME_BUTTON_PRESSED'
• 'ON_RECENT_APP_BUTTON_PRESSED' - that button that lists your apps

import { DeviceEventEmitter } from 'react-native'

class ExampleComponent extends Component {
  ...
  componentDidMount() {
    DeviceEventEmitter.addListener(
     'ON_HOME_BUTTON_PRESSED',
     () => {
       console.log('You tapped the home button!')
    })
  }
  ...
}

• Export event names and listener
• Support Other Buttons - e.g navigation button

Jack's Stackoverflow post - [https://stackoverflow.com/questions/8881951/detect-home-button-press-in-android]