Get images on a page an download them

download-images.js

// Select a NodeList of image elements 
var selector = 'ul.pages li img[src]'; // Images with src nested in <li> els in the <ul> with pages class
var images = document.querySelectorAll(selector);

function saveAll(images) {
  for(var i=0; i<images.length; i++) {
    var image = images[i];
    saveImageAs(i+1, images[i].src); // use index+1 as their name for page number approximation
  }
}

function saveImageAs(name, src) {
  var link = document.createElement('a');
  link.href = src;
  link.download = name;
  document.body.appendChild(link);
  link.click();
}