How to place an Image on top of other Image in React Native?

I have the same issue, I used an <ImageBackground>

<View style={{height: 55,width: 55,justifyContent: 'center',alignItems: 'center'}}>

   <ImageBackground  source={{uri:this.state.image1}} style={{height: 50,width: 50}}>

            <View style={{flex: 1,justifyContent: 'flex-end',alignItems: 'flex-start'}}> //here you can change position of image with justifyContent and alignItems
                 <Image
                  source={ {uri:this.state.image2}}
                  style={{width: 20 , height: 20 ,alignItems: 'center',justifyContent: 'center',borderWidth: 1,borderColor: '#fff',borderRadius: 30}} />
            </View>

    </ImageBackground>

</View>

Rather than wrapping your content in the <Image>, I think you would be better off wrapping that in an absolutely positioned element and having that stretch to cover the screen.

<View style={styles.container}>
  <View style = {styles.backgroundContainer}>
    <Image source = {require('./img/landing-background.jpg')} resizeMode = 'cover' style = {styles.backdrop} />
  </View>
  <View style = {styles.overlay}>
    <Text style = {styles.headline}>It should appear in front of the Background Image</Text>
    <Image style = {styles.logo} source = {require('./img/logo.png')} />
  </View>
</View>

var styles = StyleSheet.create({
  backgroundContainer: {
    position: 'absolute',
    top: 0,
    bottom: 0,
    left: 0,
    right: 0,
  },
  container: {
    flex: 1,
    alignItems: 'center',
  },
  overlay: {
    opacity: 0.5,
    backgroundColor: '#000000'
  },
  logo: {
    backgroundColor: 'rgba(0,0,0,0)',
    width: 160,
    height: 52
  },
  backdrop: {
    flex:1,
    flexDirection: 'column'
  },
  headline: {
    fontSize: 18,
    textAlign: 'center',
    backgroundColor: 'black',
    color: 'white'
  }
});

<ImageBackground style={{width:100, height:100, jsutifyContent:'center}}>
<Image/> //childimage
</ImageBackground

This would help you add a background image with an overlay of the child image, and worked perfectly fine for me.