The site you have linked to is the demo site for a company which creates JobRoller child themes, so you still actually require an instance of the AppThemes JobRoller theme to be installed in order to use the child themes they create. The company/person involved also offers some of their products in the
AppThemes marketplace here. We do appreciate you letting us know though, there certainly are people out there who try and sell our products as their own or "copy" them, but in this instance it is not the case. Thanks :)