Examine source code of send2cgeo

{
  "name": "send2cgeo",
  "version": "0.0.2resigned1",
  "manifest_version": 2,
  "description": "send2cgeo browser addon",
  "author": "Sebastian Kalinowski",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "page_action": {
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png"
    }
  },
  "content_scripts": [
    {
      "js": [
        "content_script.js"
      ],
      "run_at": "document_start",
      "match_about_blank": false,
      "all_frames": false,
      "matches": [
        "*://opencaching.pl/viewcache.php*",
        "*://www.opencaching.de/viewcache.php*",
        "*://opencaching.cz/viewcache.php*",
        "*://www.opencaching.cz/viewcache.php*",
        "*://www.opencachingspain.es/viewcache.php*",
        "*://www.opencaching.fr/viewcache.php*",
        "*://www.opencaching.it/viewcache.php*",
        "*://www.opencaching.nl/viewcache.php*",
        "*://www.opencaching.ro/viewcache.php*",
        "*://opencache.uk/viewcache.php*",
        "*://www.opencaching.us/viewcache.php*",
        "*://opencaching.us/viewcache.php*"
      ]
    }
  ],
  "permissions": [
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b088bb00-acdd-45a3-adef-a05c43c69d36}"
    }
  }
}