Examine source code of Livecore

{
  "name": "Livecore",
  "description": "Firefox extension for Livecore.io!",
  "version": "0.2",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "/js/background.js"
    ]
  },
  "icons": {
    "48": "/images/icon48.png",
    "128": "/images/icon128.png"
  },
  "permissions": [
    "tabs",
    "webRequest",
    "storage",
    "*://www.twitch.tv/*",
    "*://livecore.io/*",
    "*://api.livecore.io/*"
  ],
  "browser_action": {
    "default_popup": "/html/popup.html"
  },
  "options_ui": {
    "page": "/html/options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.twitch.tv/*"
      ],
      "run_at": "document_idle",
      "js": [
        "/js/runner.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8c2e0b5b-7b4b-430b-becb-09c75c950dc5}"
    }
  }
}