Examine source code of Always Desktop Version

{
  "manifest_version": 2,
  "name": "Always Desktop Version",
  "version": "1.0.1",
  "description": "Redirects some mobile sites to desktop sites.",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.m.wikipedia.org/*"
      ],
      "js": [
        "wikipedia_redirect.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "*://mobile.twitter.com/*"
      ],
      "js": [
        "twitter_redirect.js"
      ],
      "run_at": "document_start"
    }
  ],
  "options_ui": {
    "page": "options/options.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "alwaysdesktopversion@glotchalotch.github.io"
    }
  }
}