Examine source code of Haven Overlay

{
  "manifest_version": 2,
  "name": "Haven Overlay",
  "description": "Seeing what others don't.",
  "version": "0.9.1",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "havenoverlays@proton.me",
      "strict_min_version": "102.0"
    }
  },
  "permissions": [
    "webNavigation",
    "scripting",
    "activeTab",
    "storage",
    "*://*.bullx.io/*",
    "*://*.tinyastro.io/*",
    "*://*.lunarhosting.net/*",
    "*://*.axiom.trade/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "HAVEN",
    "default_popup": "popup.html"
  }
}