If you run a trial, you will see the text "Trial, 13 days remaining" in the plugin toolbar. If it doesn't say that, you are using a full version of the plugin.
Here's some information that explains all the symbols in the PA plugin toolbar:
PA Logo: Clicking the Plugin Alliance logo takes you to the Plugin Alliance website via your web browser if your computer is online.
License Type: The toolbar displays information about the type of license you’re running: Trial and Lease licenses will be displayed along with the number of days until expiration; there is no note for full licenses as these are unlimited.
‘$’ Icon: If you have a demo or financed version of any of our products, you can click this icon to open a browser that redirects you to the respective product page in the Plugin Alliance store; this is where you can easily purchase a product or pay your next installment without having to look it up on our website.
‘Key’ Icon: Clicking on the key icon brings up the activation dialog, allowing you to manually reauthorize a device in case of a license upgrade or addition. You can also use this feature to activate additional computers or USB flash drives.
‘?’ Icon: Clicking the ‘?’ icon opens up a context menu that links to the product manual PDF and other helpful links, e.g., to check for product updates online. You must have a PDF reader installed on your computer to read the manual. You can get a free PDF reader at www.adobe.com.