Examine source code of SuperPrice search

{
  "manifest_version": 2,
  "icons": {
    "128": "icon.png"
  },
  "name": "SuperPrice search",
  "description": "You can find products and price from multiple shops.",
  "version": "1.8.1",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "spp.html",
    "default_title": "SuperPrice search"
  },
  "permissions": [
    "contextMenus",
    "storage",
    "http://ip-api.com/json",
    "https://domisan.sakura.ne.jp/spp/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "jid1-T7zC870jgKm44A@jetpack",
      "strict_min_version": "57.0"
    }
  }
}