Examine source code of Check HN

{
  "manifest_version": 2,
  "name": "Check HN",
  "version": "1.2",
  "description": "Checks Hacker News for submission on the current url or website.",
  "homepage_url": "https://github.com/essenlive/checkHN",
  "icons": {
    "48": "icons/chy48.png",
    "96": "icons/chy96.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/chy96.png",
    "default_title": "Check HN",
    "default_popup": "popup/popup.html"
  }
}