Examine source code of FunnFinn

{
  "manifest_version": 2,
  "name": "FunnFinn",
  "version": "1.1.3",
  "description": "Denne utvidelsen forbedrer brukeropplevelsen på Finn.",
  "homepage_url": "https://github.com/tjabejohannes/FunnFinn",
  "icons": {
    "48": "icons/funnfinn.png"
  },
  "web_accessible_resources": [
    "web_accessible_resources/images/MapsGoogle.png",
    "web_accessible_resources/scripts/addPricePrArea.js"
  ],
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/funnfinn.png",
    "default_title": "Funn Finn",
    "default_popup": "popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.finn.no/*/*/ad*"
      ],
      "js": [
        "content_scripts/buttonToMaps.js"
      ]
    },
    {
      "matches": [
        "*://*.finn.no/realestate/*/search*"
      ],
      "js": [
        "content_scripts/pricePrArea.js"
      ]
    },
    {
      "matches": [
        "*://kart.finn.no/*"
      ],
      "js": [
        "content_scripts/mapPage.js"
      ]
    }
  ]
}