Examine source code of View Page Source

{
  "author": "David Pacassi Torrico",
  "manifest_version": 2,
  "name": "View Page Source (Mobile)",
  "version": "1.0.1",
  "description": "Adds the ability to open the page source in a new tab via button (Desktop) or menu (Firefox for Android).",
  "homepage_url": "https://github.com/dpacassi/view-page-source-mobile",
  "icons": {
    "40": "icons/40/app.png",
    "48": "icons/48/app.png",
    "128": "icons/128/app.png"
  },
  "browser_action": {
    "default_icon": {
      "40": "icons/40/app.png",
      "48": "icons/48/app.png",
      "128": "icons/128/app.png"
    },
    "default_title": "View Page Source"
  },
  "background": {
    "scripts": [
      "app.js"
    ],
    "persistent": true
  },
  "permissions": [
    "<all_urls>",
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0674fba3-0ed9-4848-bef8-fe151aa7285d}"
    }
  }
}