Click it > To use it just replace the usage of org.apache.wicket.markup.html.form.CheckBox with de.agilecoders.wicket.extensions.markup.html.bootstrap.form.checkboxx.CheckBoxX

CheckboxX checkboxX = new CheckboxX("checkboxX", new Model<Boolean>(true)) {
  @Override
  protected void onChange(Boolean value, AjaxRequestTarget target) {
    info("The selection is: " + value);
    target.add(feedback);
  }
};