Examine source code of Image Injector

{
  "manifest_version": 2,
  "name": "Image Injector",
  "version": "1.0",
  "description": "Injects images into the body of websites.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "view-file.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_icon": "screenshot.png",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "screenshot.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9f2c4e1d-26f1-4008-b8ec-8fdf50b4ba63}"
    }
  }
}