Examine source code of Aware Pause

{
  "manifest_version": 2,
  "name": "Mindful Pause",
  "version": "1.1.0",
  "description": "A private, personal tool that gives you a 15-minute pause and a reminder of your goals before you continue an impulsive search.",
  "incognito": "spanning",
  "permissions": [
    "webNavigation",
    "storage",
    "tabs",
    "unlimitedStorage",
    "*://*.google.com/*",
    "*://*.bing.com/*",
    "*://*.duckduckgo.com/*",
    "*://*.yahoo.com/*",
    "*://*.youtube.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "guard.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "browser_action": {
    "default_popup": "options.html",
    "default_title": "Mindful Pause — Settings",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_page": "options.html",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    "blocked.html",
    "blocked.js",
    "blocked.css",
    "game.html",
    "game.js",
    "game.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "mindfulpause2@localextensions.com"
    }
  }
}