Examine source code of eBayKleinanzeigen 12

{
  "manifest_version": 2,
  "name": "eBayKleinanzeigenHelper",
  "description": "Helping on Kleinanzeigen.",
  "version": "0.3",
  "author": "Phil Roggenbuck <me@phrogg.de>",
  "icons": {
    "36": "icons/Icon-36.png",
    "48": "icons/Icon-48.png",
    "72": "icons/Icon-72.png",
    "96": "icons/Icon-96.png",
    "144": "icons/Icon-144.png",
    "192": "icons/Icon-192.png",
    "512": "icons/Icon-512.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.ebay-kleinanzeigen.de/s-anzeige/*"
      ],
      "js": [
        "injectme.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{cf3751cb-a2cf-4c6a-9797-5b0350057a56}"
    }
  }
}