KA Google Analytics provides asynchronous tracking of your Joomla website by automatic insertion of Google Analytics Asynchronous tracking code. Goto plugin settings after installation and make sure it is published and you have entered correct Google Analytics tracking code. Make sure this plugin is enabled and specify your UA code in the plugin parameters. There is also other settings that you can learn more about by hovering over their labels.
We use KA Google Analytics plugin on this website and you can have a look at source code to check it out.