React Native Text scales the font size based on a device width

welcome: {
  fontSize: 31,
  textAlign: 'center',
  margin: 10,
},
instructions: {
  fontSize: 16,
  textAlign: 'center',
  color: '#333333',
  marginBottom: 5,
}

import React, { PropTypes } from 'react';
import { StyleSheet } from 'react-native';
import ScalableText from 'react-native-text';

const WelcomeText = ({ text }) => (
  <ScalableText style={styles.text}>{text}</ScalableText>
);

WelcomeText.propTypes = {
  text: PropTypes.string.isRequired
};

const styles = StyleSheet.create({
  text: {
    color: 'tomato',
    fontSize: 28
  }
});

export default WelcomeText;