For unlimited using you need to activate full version via one-time in-app purchase.
As Google yet does not support in-app purchases for developers/publishers in our country, we use Fortumo (www.fortumo.com) mobile payments library to provide in-app text message purchase. No text messages will be sent without your confirmation.
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?