Examine source code of History Hoard

{
  "name": "History Hoard",
  "version": "1.2",
  "manifest_version": 2,
  "description": "Keep your browsing history forever.",
  "permissions": [
    "history",
    "unlimitedStorage",
    "downloads"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "assets/icons/H128.png",
    "default_title": "History Hoard"
  },
  "icons": {
    "16": "assets/icons/H16.png",
    "32": "assets/icons/H32.png",
    "48": "assets/icons/H48.png",
    "128": "assets/icons/H128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6f974851-eccf-49ac-bd52-a1abe3e6a1c4}"
    }
  }
}