$ npm install react-native-fingerprint-change --save

$ react-native link react-native-fingerprint-change

1. In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
2. Go to node_modules ➜ react-native-fingerprint-change and add RNFingerprintChange.xcodeproj
3. In XCode, in the project navigator, select your project. Add libRNFingerprintChange.a to your project's Build Phases ➜ Link Binary With Libraries
4. Run your project (Cmd+R)<

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

• Add import com.toyberman.fingerprintChange.RNFingerprintChangePackage; to the imports at the top of the file
• Add new RNReactNativeAccessibilityPackage() to the list returned by the getPackages() method

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

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

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

     compile project(':react-native-fingerprint-change')
   

import RNFingerprintChange from 'react-native-fingerprint-change';

// How to use the module 
RNFingerprintChange.hasFingerPrintChanged((error, fingerprintHasChanged)=>{
	if(fingerprintHasChanged) {
		// do what you need when fingerprint change has been detected
	}
})


example:

import {
    AppState,
} from 'react-native';

import RNFingerprintChange from 'react-native-fingerprint-change';


class example extends Component {

	constructor(props) {
		super(props)
		this.state = {
			appState: AppState.currentState,
		}
	}

	componentDidMount() {
        AppState.addEventListener('change', this._handleAppStateChange);
	}

	componentWillUnmount() {
    	AppState.removeEventListener('change', this._handleAppStateChange);
    }

	_handleAppStateChange = (nextAppState) => {
		if (this.state.appState.match(/inactive|background/) && nextAppState === 'active') {
			//App has come to the foreground!
			RNFingerprintChange.hasFingerPrintChanged((error) => {},(fingerprintHasChanged)=>{
			if(fingerprintHasChanged) {
				// do what you need 
			}
		})
		}
		this.setState({appState: nextAppState});
	}
}