Examine source code of Pull to Refresh

{
  "name": "Pull to Refresh",
  "description": "You pull and it refreshes on Android. It basically injects code from this library in all the pages https://www.boxfactura.com/pulltorefresh.js/. The icon is Refresh by gb on noun project.",
  "manifest_version": 2,
  "version": "1.0.3resigned1",
  "homepage_url": "https://github.com/andreicristianpetcu/firefox_pull_to_refresh",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "pulltorefresh.js",
        "apply_pulltorefresh.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b55e30ee-6692-40c4-9c09-77a0b42cb268}"
    }
  }
}