The project has two types of licenses: open-source and commercial. In general, the project is free for non-commercial, trial and educational use, and paid for commercial use.
The open source license can be used to create open source, trial and personal projects. The project uses the GPLv3 open source license.
Please note that releasing your application that uses this project under the GPLv3 license, in turn, requires your application to be licensed under the GPLv3 license.
The commercial license should be used to create commercial products and applications, without the provisions of the GPLv3 license. With the commercial license, your code is kept proprietary, to yourself. If you want to use this project to develop commercial websites, themes, projects, and applications, the commercial license is the way to go.