No, you don't need to purchase the
Jobsapp child theme in order for JobRoller to be responsive.
Jobsapp is a JobRoller child theme, so this means you need to have an instance of JobRoller installed in order for it to function. You can read more about
how child themes work here.
The
Job Super Search plugin is a separate purchase to JobRoller, and no, the theme itself does not have this functionality already built into it.
If you provide a theme translation we can offer a 40% discount off your theme purchase as outlined on our
languages page, however this does not apply to additional marketplace purchases such as Jobapps. Thanks.