Examine source code of VK scrobbler

{
  "name": "VK scrobbler",
  "description": "Скробблинг проигрываемой на vk.com музыки на last.fm",
  "icons": {
    "128": "blocks/logo/logo_128.png"
  },
  "version": "2.1.1.2resigned1",
  "manifest_version": 2,
  "minimum_chrome_version": "41.0",
  "background": {
    "scripts": [
      "blocks/namespace/namespace.js",
      "components/md5.min.js",
      "blocks/options/options-handlers.js",
      "blocks/log/log.js",
      "blocks/lastfm-api/lastfm-api__client.js",
      "blocks/lastfm-api/lastfm-api__config.js",
      "blocks/lastfm-api/lastfm-api.js",
      "blocks/analytics/analytics.js",
      "blocks/bus/bus__background.js",
      "blocks/content/content__messages.js",
      "blocks/background/background__auth.js",
      "blocks/background/background__actions.js",
      "blocks/background/background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "vk-scrobbler@stsdc.org",
      "strict_min_version": "47.0"
    }
  },
  "options_ui": {
    "page": "blocks/options/options.html"
  },
  "permissions": [
    "tabs",
    "notifications",
    "storage",
    "*://*.vk.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.vk.com/*"
      ],
      "js": [
        "blocks/namespace/namespace.js",
        "blocks/options/options-handlers.js",
        "blocks/log/log.js",
        "blocks/indicators/indicators__utils.js",
        "blocks/indicators/indicators.js",
        "blocks/bus/bus__content.js",
        "blocks/content/content__messages.js",
        "blocks/content/content__bus-wrapper.js",
        "blocks/content/content__script-injector.js",
        "blocks/content/content__utils.js",
        "blocks/content/content__player-handlers.js",
        "blocks/content/content.js"
      ],
      "css": [
        "blocks/indicators/indicators.css"
      ]
    }
  ],
  "homepage_url": "http://vk.com/vk_scrobbler",
  "web_accessible_resources": [
    "blocks/indicators/__icon/*",
    "blocks/indicators/__icon/indicators__icon-tweet.png",
    "blocks/indicators/__icon/indicators__icon-love.png",
    "blocks/indicators/__icon/indicators__icon-unlove.png",
    "blocks/indicators/__icon/indicators__icon-disabled.png",
    "blocks/indicators/__icon/indicators__icon-equalizer.gif",
    "blocks/indicators/__icon/indicators__icon-pause.png",
    "blocks/indicators/__icon/indicators__icon-check-blue.png",
    "blocks/namespace/*",
    "blocks/namespace/namespace.js",
    "blocks/options/options-handlers.js",
    "blocks/log/log.js",
    "blocks/vk-inner/vk-inner__player.js",
    "blocks/vk-inner/vk-inner.js"
  ]
}