Examine source code of MeasureMate

{
  "manifest_version": 2,
  "name": "MeasureMate",
  "version": "1.5",
  "description": "Easy to use browser extension to convert units",
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "browser_action": {
    "default_area": "navbar",
    "default_popup": "popup/index.html",
    "default_title": "MeasureMate",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0f87fb49-11ab-43b3-be5f-d0dbd46606b8}"
    }
  }
}