Examine source code of Reverse Youtube

{
  "manifest_version": 2,
  "name": "Reverse Youtube",
  "description": "Replacing Youtube playback window and right column",
  "version": "1.0",
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{661071a6-89cb-4936-9096-816f4bb9871e}"
    }
  }
}