Your WordPress website can become mobile responsive at a click of a button

Just install the Jetpack plugin and activate the Mobile Theme module.  Smartphone users will now automatically see the mobile theme with an option to view the full site.

This is really useful if your theme is not designed to be responsive. This feature does not automatically create a mobile looking version of your theme. It only gives the visitor a greater reading experience by optimizing the content of your site for a smaller screen. If you don’t like this feature, it can be deactivated just as easily.