Plugin has full support for Google Fonts service providing open source and free to use fonts for websites. Current plugin version contains the latest list with 800+ fonts from Google. But, the plugin supports auto update of fonts list, so any new fonts added to Google Web Fonts library will be available to you without the need to update the plugin.
For auto updater to work, you need a valid API key from Google (available for free from your Google account console, link provided in the plugin). You can set the number of days for update check.
For auto update feature, you need API key and you can set the number of days to keep cached fonts and avoid checking for new fonts too often (Google usually makes updates 2-3 times a month).
To load fonts, the plugin can use standard style files loading, or asynchronous loading using WebFont Loader. WebFont Loader is developed by Adobe and Google and can load both Google Fonts and Typekit kits.