Unfortunately we do not have a New World Empires app. It's only playable in your web browser, and most playable on your computer. It is possible however to play the game on your mobile in the web browser, but this is not the most easiest way to play it (lots of rotating your screen).
Its playable on smartphones. Just use the webbrowser of ur smartphones. But: The game is still the Alpha version-and will be Alpha forever. U cant see the whole screen, so u cant build or recruit anything, but u can move ur units and watch how the battles are going.