Examine source code of * Page In Between

{
  "manifest_version": 2,
  "name": "* Page In Between",
  "version": "0.1.0",
  "browser_action": {
    "default_icon": {
      "32": "img/tree.png"
    },
    "default_title": "* Page In Between"
  },
  "background": {
    "scripts": [
      "index.js"
    ]
  },
  "permissions": [
    "webNavigation",
    "tabs"
  ],
  "icons": {
    "32": "img/tree.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{a7cfefe2-3939-43ef-9fb0-bc1812a1c858}"
    }
  }
}