Greasemonkey is really great to customize websites for your [weird] usage pattern. (Tampermonkey[0] works in Chrome, Microsoft Edge, Safari, Opera Next, and Firefox)

XHR is a pretty decent api that ignores CORS[1]

  GM.xmlHttpRequest({
    method: "GET",
    url: "http://www.example.com/",
    onload: function(response){alert(response.responseText)}
  });

[0] - https://www.tampermonkey.net/ [1] - https://wiki.greasespot.net/GM.xmlHttpRequest