QSDA Pro may be used without purchasing a license, with some restrictions. 

•Application size is limited to 100 visualization objects.  Applications larger than this will not be analyzed.

•Personal sheets and their associated objects will not be processed.

•The QSDA web interface will only be available in local mode (localhost).

Purchasing a license will remove the restrictions.  Learn about license options and purchase securely on-line at  https://easyqlik.com/qsda/