Examine source code of demystify

{
  "manifest_version": 2,
  "name": "demystify",
  "description": "browser extension",
  "version": "1.0.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "devtools_page": "devtools.html",
  "permissions": [
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c863bfb7-7f77-4029-ac0a-3f6ef8881131}"
    }
  }
}