It's a well known challenge with using extensions. They might not be as well polished and well developed and consistent when it comes to "Responsive Web Design" due to the fact that they are not necessarily production level development efforts.
So either the author(s) or someone else must face the challenge on enhancing the extension to address this issue.
I find it best best to write a mashup for use on smart phones, as then one has full control as per its responsive behaviour, avoiding the issues of Qlik out of the box on small screens.
This does have downside of the time, effort and skill sets needed to write the mashup.
