Examine source code of TwitterLatest

{
  "manifest_version": 2,
  "name": "TwitterLatest",
  "version": "1.0.2",
  "description": "Automatically switch Twitter feed to “Latest Tweets” ✨",
  "browser_action": {
    "default_icon": "icon128.png"
  },
  "icons": {
    "128": "icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/home",
        "https://mobile.twitter.com/home"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}