Examine source code of EMP-Plug

{
  "manifest_version": 2,
  "name": "EMP-Plug",
  "description": "EMP-Plug",
  "version": "1.4resigned1",
  "icons": {
    "128": "EMP_Plag_Ico_128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.emp-game.ru/*",
        "*://*.ok.ru/game/empgame/*",
        "*://*.vk.com/app4399185/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b937e706-e605-439b-a74d-3ac15fe3ca93}"
    }
  }
}