To enable mobile plugin loading you need to go to the settings page under Settings->Plugin Organizer in the WordPress admin. Click the button in the box titled “Selective Mobile Plugin Loading” and set it to “On” and click the “Save Settings” button. Then click the “Mobile User Agents” tab and add the user agent strings that you would like to target with the mobile settings.
A user agent string is what is presented by a browser when it visits your page. You can actually use this to target any browser. For instance if you wanted to present different plugins when Google or Yahoo come to your site then you could just put Google or Yahoo in the box. Or you can put in the full user agent string. It is a case insensitive string match on whatever you put in the box. Separate each user agent string with a new line. If you need a list of mobile user agents go to http://www.zytrax.com/tech/web/mobile_ids.html or you can search for a list of mobile browser user agents. A default list of words that should match most mobile devices is set when Plugin Organizer is installed.