Examine source code of Bulk Texter Pro

{
  "manifest_version": 2,
  "name": "Bulk Texter Pro",
  "short_name": "Bulk Texter+",
  "description": "Send texts with a personal touch, at scale, using the phone number you already have.",
  "version": "3.5.14",
  "background": {
    "scripts": [
      "lib/secrets.js",
      "lib/store.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Bulk Texter Pro",
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://app.bulktexterpro.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "contentScripts/utilities.js",
        "lib/store.js",
        "lib/secrets.js",
        "contentScripts/api.js"
      ],
      "all_frames": false
    },
    {
      "matches": [
        "https://dialpad.com/*",
        "https://voice.google.com/*",
        "https://messages.google.com/*",
        "https://www.textnow.com/*",
        "https://billing.bulktexterpro.com/*",
        "https://docs.google.com/picker*"
      ],
      "run_at": "document_start",
      "world": "MAIN",
      "js": [
        "contentScripts/keepWindowActive.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "https://dialpad.com/*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "lib/store.js",
        "contentScripts/sendQueue.js",
        "contentScripts/platforms/dialpad.js"
      ],
      "all_frames": false
    },
    {
      "matches": [
        "https://voice.google.com/*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "lib/store.js",
        "contentScripts/sendQueue.js",
        "contentScripts/platforms/googleVoice.js"
      ],
      "all_frames": false
    },
    {
      "matches": [
        "https://messages.google.com/*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "lib/store.js",
        "contentScripts/sendQueue.js",
        "contentScripts/platforms/googleMessages.js"
      ],
      "all_frames": false
    },
    {
      "matches": [
        "https://www.textnow.com/*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "lib/store.js",
        "contentScripts/sendQueue.js",
        "contentScripts/platforms/textNow.js"
      ],
      "all_frames": false
    },
    {
      "matches": [
        "https://billing.bulktexterpro.com/*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "contentScripts/bulkTexterProBilling.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "https://docs.google.com/picker*"
      ],
      "js": [
        "contentScripts/utilities.js",
        "contentScripts/platforms/googleDocsFileUpload.js"
      ],
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "contentScripts/injectedModal.html",
    "contentScripts/platforms/textNowUserScript.js"
  ],
  "icons": {
    "48": "icon48.png",
    "128": "icon128.png",
    "612": "icon.png"
  },
  "permissions": [
    "alarms",
    "scripting",
    "storage",
    "unlimitedStorage",
    "https://app.bulktexterpro.com/*",
    "https://dialpad.com/*",
    "https://messages.google.com/*",
    "https://voice.google.com/*",
    "https://www.textnow.com/*",
    "https://billing.bulktexterpro.com/*",
    "https://docs.google.com/*"
  ],
  "optional_permissions": [
    "https://app.zoom.us/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{027f41ab-bff9-4619-ac9e-8a7defaed9a0}",
      "strict_min_version": "58.0"
    }
  }
}