Examine source code of Hacker News Watcher

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "gerardes@firefox.com",
      "strict_min_version": "48.0"
    }
  },
  "name": "Hacker News Watcher",
  "version": "0.80.0",
  "description": "Keep track of your favorite subjects on Hacker News.",
  "icons": {
    "128": "img/icon_rnd.png"
  },
  "background": {
    "scripts": [
      "vendor/gDelay.js",
      "basehelpers/StoriesHelper.js",
      "basehelpers/StorageHelper.js",
      "basehelpers/SettingsHelper.js",
      "basehelpers/FetchHelper.js",
      "basehelpers/BadgeHelper.js",
      "basehelpers/PreMatchedListHelper.js",
      "modules/favo/FavoHelper.js",
      "modules/matched/MatchedHelper.js",
      "modules/new/NewHelper.js",
      "modules/top/TopHelper.js",
      "modules/watchers/WatchersHelper.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "img/icon_rnd.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "https://hacker-news.firebaseio.com/"
  ]
}