Examine source code of Friction

{
  "name": "Friction",
  "version": "0.4",
  "manifest_version": 2,
  "description": "Introduce friction to those sites you use habitually but want to use less.",
  "icons": {
    "128": "icon_128.png"
  },
  "background": {
    "scripts": [
      "background.js",
      "options.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "applications": {
    "gecko": {
      "id": "{4cee5697-0e8a-4d7f-ac04-348485072145}"
    }
  }
}