Here's an example with the Jquery append function that will add an extra div at the left bottom of the widget with id 36 but you can change it to the class or id from every page or widget in your visualization.
To use it you can add it this line of script to your custom Javascript.
$(function() {
$("#widget-36").append('<div style="position: absolute; bottom: 0; left: 0; z-index: 60;">This text was added to my widget from script</div>');
});
To use it you can add it this line of script to your custom Javascript.
$(function() {
$("#widget-36").append('<div style="position: absolute; bottom: 0; left: 0; z-index: 60;">This text was added to my widget from script</div>');
});