Examine source code of TikiTak

{
  "manifest_version": 2,
  "name": "TikiTak",
  "version": "1.2.1",
  "description": "Limit browsing time in websites of your choice",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "tikitak_background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "tikitak.js"
      ]
    }
  ],
  "options_ui": {
    "page": "settings.html"
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs"
  ],
  "page_action": {
    "default_title": "Set a time limit for this site",
    "default_icon": "icons/clock.png",
    "browser_style": true
  },
  "applications": {
    "gecko": {
      "id": "tikitak2019@example.com"
    }
  }
}