Examine source code of Save to Koofr

{
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "default_locale": "en",
  "description": "__MSG_extDesc__",
  "version": "1.2.5",
  "permissions": [
    "contextMenus",
    "storage",
    "activeTab",
    "http://*/*",
    "https://*/*",
    "<all_urls>"
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_title": "__MSG_extName__",
    "default_icon": "icon128.png"
  },
  "background": {
    "scripts": [
      "lib/jquery-3.1.1.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "css": [
        "lib/toastr.min.css",
        "koofr.css"
      ],
      "js": [
        "lib/jquery-3.1.1.js",
        "lib/toastr.min.js",
        "content_script.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "lib/*",
    "content_script.js",
    "koofr.css",
    "present"
  ],
  "commands": {
    "screenshot": {
      "suggested_key": {
        "default": "Ctrl+Shift+K",
        "mac": "Command+Shift+K"
      },
      "description": "__MSG_screenshotCmdDesc__"
    },
    "saveLargestImage": {
      "suggested_key": {
        "default": "Ctrl+Shift+L",
        "mac": "Command+Shift+L"
      },
      "description": "__MSG_screenshotCmdDesc__"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1646f5a4-e17e-436b-8abb-f6929a2a6082}"
    }
  }
}