I love your template! Thanks so much for all the hard work you put into it!

I am using a mailing list company, MadMimi. I'd like to add something on my site that allows people to subscribe to the mailing list. I created a sidebox, which works fine. However, it only shows up when I view my site on a desktop, not on a mobile phone. I understand that it wouldn't make sense for all the left sideboxes to show up on a phone. But I'm wondering if anyone has any suggestions on a strategy for this. I'd like to have a signup for the mailing list show up on a phone as well. Would you suggest putting the signup in the footer instead of a sidebox? Or is there a way to put it in the footer only for mobile viewing, but to leave it in a sidebox for desktop viewing? If so, how would I specify that it should only be displayed in the footer for mobile viewing? I only see a single tpl_footer.php in
includes/templates/winchester_responsive/common/. Thanks in advance for any suggestions!