If you ever wanted to make your WordPress browsing experience better for smartphone users, you should consider using WPtouch plugin.
After you have installed this plugin to your WordPress installation you will be able to choose default language for your website. Plugin comes with three languages (English, Spanish and French) by default, but you can translate everything by yourself because there is .pot file included (go to lang/src folder).
In addition, there are even more great settings to check. For example, you can change which page should be used as homepage, you can also change your site title text and choose which meta information to show for your guests. You even have some styling options: changing header, background, text colors and styles.
There is not only free version available from WordPress extend directory. If you are not satisfied with the functionality you get, you can try WPtouch Pro version. There are different plans and pricing from only $39 to unlimited users developer license which is up to $199. Creators give lifetime updates and guarantee for just one price.
You can learn more about Pro version at their official website.