Examine source code of Dezoomify

{
  "manifest_version": 2,
  "name": "Dezoomify",
  "version": "1.0.1",
  "description": "Download zoomable images from web pages",
  "icons": {
    "24": "icons/color/icon-24.png",
    "96": "icons/color/icon-96.png",
    "128": "icons/color/icon-128.png",
    "512": "icons/color/icon-512.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "24": "icons/grey/icon-24.png",
      "96": "icons/grey/icon-96.png",
      "128": "icons/grey/icon-128.png",
      "512": "icons/grey/icon-512.png"
    },
    "default_title": "Dezoomify is inactive. Click to activate zoomable image search."
  },
  "permissions": [
    "activeTab",
    "webRequest",
    "contextMenus",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{11275cf8-f86a-4560-9307-77750b33620f}"
    }
  }
}