Examine source code of SimpleNoImg

{
  "manifest_version": 2,
  "name": "NoImg2",
  "version": "1.3resigned1",
  "description": "Disable some image-showing mechanisms. Pages become uglier, but calmer.",
  "browser_action": {
    "default_icon": {
      "19": "icons/no_img.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "no-img.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d8475f0f-094a-4951-8b32-a140f44cabab}"
    }
  }
}