Examine source code of Superhero Wallet

{
  "name": "Superhero",
  "description": "Superhero Wallet",
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "strict_min_version": "53.0"
    }
  },
  "permissions": [
    "storage",
    "unlimitedStorage",
    "videoCapture",
    "activeTab",
    "clipboardWrite",
    "contextMenus",
    "notifications",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "webNavigation",
    "*://*.chain/*",
    "*://*.google.com/*",
    "https://*.twitter.com/*",
    "https://twitter.com/*",
    "https://*.youtube.com/watch?v=*",
    "https://wallet.superhero.com/*"
  ],
  "icons": {
    "48": "./icons/icon_48.png",
    "128": "./icons/icon_128.png"
  },
  "browser_action": {
    "default_title": "Superhero",
    "default_popup": "index.html"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "run_at": "document_start",
      "all_frames": true,
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "js/inject.js"
      ]
    },
    {
      "run_at": "document_start",
      "matches": [
        "https://*.twitter.com/*",
        "https://twitter.com/*"
      ],
      "js": [
        "js/twitter.js"
      ]
    },
    {
      "run_at": "document_start",
      "matches": [
        "https://*.youtube.com/watch?v=*"
      ],
      "js": [
        "js/youtube.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "js/inject.js",
    "CameraRequestPermission.html",
    "other/tipButton.css",
    "index.html"
  ],
  "version": "0.9.6",
  "content_security_policy": "script-src 'self' ; object-src 'self'"
}