I have managed to add some JavaScript that I found here and almost get my promoted links to be responsive.
The only issue is that when my screen gets below a resolution of approximately 900px the promoted links end up on a single line each.
I have seen the answer to the question asked within Stack Overflow but do not understand where it is I need to add the "!important" tag in order to override the SharePoint CSS which appears to be causing this.
Could anyone please advise on how to fix this.
JavaScript:
$(document).ready(function () {
$('#promotedlinksbody_WPQ7').removeClass('ms-promlink-body');
$('#promotedlinksbody_WPQ7').addClass('row container-fluid');
$('#promotedlinksbody_WPQ7').children().removeClass('ms-tileview-tile-root');
$('#promotedlinksbody_WPQ7').children().addClass('col-md-4 tilesresponsive');