Hello,
You can easily do this at Joomla backend. As TemplateToaster provides the bootstrap support, so you can add these classes ' hidden-lg hidden-md hidden-sm visible-xs ' in Module class suffix for modules.
Go to joomla admin -> Extensions -> Module Manager -> Click on your module (for example search module) -> Advanced -> Module class suffix -> add these classes " hidden-lg hidden-md hidden-sm visible-xs " -> Save