I was recently on a comic website and was struggling heavily with their poor UI layout that made navigating pages quite painful so I wrote a tiny tampermonkey script to add in WASD style navigation. This particular site has both between issue and in-issue Previous/Next, so there is a “next page” and a “next comic” button.

For compatibility this is written as an ES5 IIFE with ye-olde dom events instead of some sexier DOM 3 tricks. Links are grabbed by text content which is expensive but this particular site didn't have consistent classes or ids. I use focusin and focusout to make sure we aren't in a textfield when navigating so you can still use search and whatnot (and it's way cheaper/easier than patching every input with custom events and pretty well supported in most browsers).

For some potential upgrades, move to ES6, use compositionstart and compositionend, and use the new keyboard API instead of fighting keyCode.

// ==UserScript==
// @name         e6 key
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  add keyboard navigation
// @include        *://blah.com/*
// @exclude     *.json
// @exclude     *.xml
// @grant        none
// ==/UserScript==

(function(window, document) {
  'use strict';
  var isEditing = false;

  //patch so we can disable ourselves on editing events
  document.addEventListener('focusin', function(){
    isEditing = true;
  });
  document.addEventListener('focusout', function(){
    isEditing = false;
  });

  function getLinkByText(text) {
    var aTags = document.getElementsByTagName("a");

    for (var i = 0; i < aTags.length; i++) {
      if (aTags[i].textContent === text) return aTags[i];
    }
  }

  document.addEventListener('keydown', function(event) {
    var target;
    if(isEditing) return;

    switch(event.keyCode) {
      case 87: //w
        window.scrollBy(0, -250);
      break;
      case 83: //s
        window.scrollBy(0, 250);
      break;
      case 81: //q
        target = getLinkByText('Previous');
        if(target) return target.click();
        event.preventDefault();
      break;
      case 69: //e
        target = getLinkByText('Next');
        if(target) return target.click();
        event.preventDefault();
      break;
      case 65: //a
        target = getLinkByText('<< Previous');
        if(target) return target.click();
        event.preventDefault();
      break;
      case 68: //d
        target = getLinkByText('Next >>');
        if(target) return target.click();
        event.preventDefault();
      break;
      case 82: //r
        target = getLinkByText('Random');
        if(target) return target.click();
        event.preventDefault();
      break;
    }
  });

})(window, document);