Examine source code of CORS Everywhere

{
  "manifest_version": 2,
  "name": "CORS Everywhere",
  "version": "18.11.13.2044resigned1",
  "author": "spenibus",
  "description": "Bypass CORS restrictions by altering http responses.",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "CORS Everywhere",
    "default_icon": {
      "48": "media/button-48.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "applications": {
    "gecko": {
      "id": "cors-everywhere@spenibus"
    }
  }
}