If you plan to publish your app, there's one thing you're going to need sooner or later: internationalization (I18n) and localization (L10n). That's what Alexander Zaytsev has brought to React Native by integrating i18n-js.

react-native-i18n on GitHub

Integrates I18n.js with React Native. Uses the device's locale as default.

var I18n = require("react-native-i18n");

var Demo = React.createClass({
  render: function () {
    return <Text>{I18n.t("greeting")}</Text>;
  },
});

I18n.translations = {
  en: {
    greeting: "Hi!",
  },
  fr: {
    greeting: "Bonjour!",
  },
};