Sneak Peek

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Sneak Peek",
  "version": "2.0.1",
  "manifest_version": 3,
  "description": "View the last message sent in fb messenger or instagram without marking it as read.",
  "icons": {
    "16": "images/spy_16px.png",
    "32": "images/spy_32px.png",
    "64": "images/spy_64px.png",
    "128": "images/spy_128px.png"
  },
  "action": {},
  "content_scripts": [
    {
      "matches": [
        "https://www.instagram.com/direct/*",
        "https://www.messenger.com/t/*"
      ],
      "css": [
        "style.css"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ]
}