Examine source code of ProWritingAid

{
  "manifest_version": 2,
  "name": "ProWritingAid Grammar Checker & Writing Coach",
  "description": "Gain confidence in your writing with the best grammar checker and paraphrasing tool that works wherever you do.",
  "version": "2.8.16692",
  "icons": {
    "16": "assets/icons/pwa-logo-16x16.png",
    "48": "assets/icons/pwa-logo-48x48.png",
    "128": "assets/icons/pwa-logo-128x128.png"
  },
  "background": {
    "scripts": [
      "./common.js",
      "./background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "19": "assets/icons/pwa-logo-19x19.png",
      "38": "assets/icons/pwa-logo-38x38.png"
    },
    "default_title": "ProWritingAid",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "cookies",
    "http://*/*",
    "https://*/*",
    "storage",
    "clipboardRead",
    "clipboardWrite",
    "notifications"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "./polyfills.js"
      ],
      "match_about_blank": true,
      "run_at": "document_start",
      "all_frames": true
    },
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "./prepare.js"
      ],
      "match_about_blank": true,
      "run_at": "document_start",
      "all_frames": true
    },
    {
      "matches": [
        "*://docs.google.com/document/*"
      ],
      "js": [
        "./gdocs-patch.js"
      ],
      "match_about_blank": true,
      "run_at": "document_start",
      "all_frames": false,
      "world": "MAIN"
    },
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "./ping.js"
      ],
      "match_about_blank": true,
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "content_security_policy": "script-src 'unsafe-eval' 'self' https://az416426.vo.msecnd.net; object-src 'self'",
  "web_accessible_resources": [
    "img/*",
    "img/icons/*",
    "css/*",
    "fonts/*",
    "assets/*",
    "assets/js/*",
    "images/*",
    "/*",
    "/webeditor.js",
    "/common.js"
  ],
  "applications": {
    "gecko": {
      "id": "tech@prowritingaid.com",
      "strict_min_version": "58.0"
    }
  }
}