Well there is Gimp with the DBP plugin that does the same and it is absolutly free!
It goes under the name of gimp-dbp in the Arch repo.
In fact Gimp is pretty much covering everything in this area with all the available plugins.
And then there is Phatch That really is a specialist on this for every platform.
Phatch handles all popular image formats and can duplicate (sub)folder hierarchies. It can batch resize, rotate, apply shadows, perspective, rounded corners and perform 35 further actions automatically. The Phatch website has extensive documentation and also allows you to install specific extensions. Because of Phatch’s excellent documentation, any user from beginner to advanced will find the software easy to use and extend.
These programs work on every platform Windows Mac and Linux - yours only works on Windows
It just does not make sense to pay 15 dinero for an inferior program - thank you for helping me illustrate that.
But if you have the $14.95 to spend, it makes a lot of sense donating it to one of the two projects above because it will ensure further development.