Examine source code of Touchscreen Swipe Navigation

{
  "manifest_version": 2,
  "name": "Touchscreen Swipe Navigation",
  "author": "Francesco Pasa",
  "version": "1.1",
  "description": "Adds touchscreen gestures (not trackpad or mouse gestures) to navigate back, forward and reload the page to Firefox. The gestures provided are all single finger, using swipes and pull down from the top of the page, at any position in the page. This makes it easy to navigate when holding the device with both hands.",
  "icons": {
    "128": "assets/icon.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "navigate.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "touchscreen-swipe-navigate@fpasa.xyz"
    }
  },
  "web_accessible_resources": [
    "assets/arrow-circle-left.svg",
    "assets/arrow-circle-right.svg",
    "assets/arrow-clockwise.svg"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage"
  ]
}