Find a keyword on a page

keyword-finder.user.js

// ==UserScript==
// @name     KeywordFinder
// @version  1
// @grant    none
// @match    https://news.ycombinator.com/*
// ==/UserScript==

(function(keyword) {
  const counter = document.createElement('p')
  counter.style.position = 'fixed'
  counter.style.top = '0'
  counter.style.right = '0'
  counter.style.backgroundColor = '#1A5EC6'
  counter.style.color = '#fff'
  counter.style.fontSize = '18px'
  counter.style.padding = '9px'
  counter.style.margin = '0'
  const occurrences = document.body.innerHTML.match(new RegExp(keyword, 'gi'))

  if (occurrences) {
    counter.innerText = `${keyword}: ${occurrences.length}`
    document.body.appendChild(counter)
  }
})('dnsimple')