You have posted in the SimpleViewer v2 forum (not the SimpleViewer-Pro v2 forum).
I do not know if this is intentional or not but the imageClickMode configuration option is available in SimpleViewer-Pro only (not SimpleViewer-Standard, the free version).
If you have SimpleViewer-Pro, you can access this option within the svBuilder-Pro interface in the 'Customize -> Main Image' section (without the need to modify any code by hand).
Make sure that you have a linkURL specified for each image as these are the URLs that SimpleViewer will use when the user clicks on an image.
how do I access the XML files?
If you want to modify your gallery's XML file manually, then the XML file will likely be called 'gallery.xml' and can be found directly in the gallery folder. You can open the XML file in any plain text editor (such as Windows Notepad). You can then add imageClickMode="OPEN_URL" as an attribute to the opening <simpleviewergallery> tag, e.g.
<simpleviewergallery title="Test Gallery" imageClickMode="OPEN_URL">
Secondly-The gallery does not work on mobile devices, is it none responsive or is this something I need to update in the settings?
SimpleViewer will automatically use the Mobile Player to display your gallery on mobile devices (and in browsers which do not have Adobe Flash Player installed and enabled). Please note that the Mobile Player differs from the Flash Player.
Please see these FAQs:
When I view my gallery I see a grid of thumbnails, not the layout I specified. Why?
The mobile player layout does not match the Flash player layout. Why not?
If you have embedded your gallery in an existing web page alongside other content and your gallery does not function, you can validate your web page's code with the W3C Markup Validation Service and fix any HTML errors that are reported. This may help.
If you continue to experience difficulties, please post the URL of your gallery so that I can take a look and help further.
SimpleViewer Support Team