Examine source code of sentinel.sale

{
  "manifest_version": 2,
  "name": "sentinel.sale",
  "description": "Track e-commerce product prices and get notified when they go on sale.",
  "version": "1.0.2",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "storage",
    "sidePanel",
    "activeTab",
    "https://sentinel.sale/*"
  ],
  "sidebar_action": {
    "default_panel": "sidepanel.html",
    "default_title": "sentinel.sale"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "extension-support@sentinel.sale",
      "data_collection_permissions": {
        "required": [
          "browsingActivity"
        ],
        "optional": []
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "sentinel.sale",
    "default_popup": "popup.html"
  }
}