Examine source code of Hide Images per Tab

{
  "manifest_version": 2,
  "name": "Hide Images per Tab",
  "homepage_url": "https://github.com/FocusZilla/HideImagesPerTab",
  "version": "0.5.3resigned1",
  "applications": {
    "gecko": {
      "id": "HideImagesPerTab@FocusZilla.github.io",
      "strict_min_version": "57.0a1"
    }
  },
  "description": "Hide/show images, plugins and videos. Configurable per tab.",
  "browser_action": {
    "browser_style": true,
    "default_icon": "buttons/show_images_show_videos.svg",
    "default_title": "Hide/show images, plugins/videos. New tabs.",
    "default_popup": "popup.html?type=default"
  },
  "page_action": {
    "browser_style": true,
    "default_icon": "buttons/show_images_show_videos.svg",
    "default_title": "Hide/show images, plugins/videos. Current tab.",
    "default_popup": "popup.html?type=tab"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "permissions": [
    "tabs",
    "sessions",
    "storage",
    "<all_urls>"
  ],
  "icons": {
    "48": "buttons/show_images_show_videos.svg",
    "96": "buttons/show_images_show_videos.svg"
  },
  "author": "Peter Kehl"
}