Website Optimizer is shareware. 
Each month, the first 1000 processed files are free. 
Afterward a watermark is added to the result.
Go to https://www.japplis.com/website-optimizer/pricing.html for more details.

Japplis grants you a non-transferable, non-exclusive right to use the software.
You are not allowed to sell, license or sub-license it to any third party.
It is not allowed to use Website Optimizer in any other software.

You may copy or distribute the shareware version of Website Optimizer provided
that it's an unmodified and complete version, as downloaded from 
https://www.japplis.com/website-optimizer/

To the extent permitted by law, THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT 
WARRANTIES WHETHER EXPRESSED OR IMPLIED. THE AUTHOR SHALL NOT BE LIABLE FOR 
ANY DAMAGE RESULTING OF THE USE OF WEBSITE OPTIMIZER.
It's prohibited to decompile the code.

Website Optimizer is released with libraries which have other licenses.
The list of the libraries and their licenses are listed in
Help -> About -> Licenses -> Third-Party libraries