Examine source code of TwitterWiper

{
  "description": "Wipe down anoying toast message from twitter timeline",
  "manifest_version": 2,
  "name": "TwitterWiper",
  "version": "1.1.519",
  "homepage_url": "https://github.com/ingee/twitter-wiper.git",
  "icons": {
    "64": "icons/icons8-wiper-64.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.x.com/*"
      ],
      "js": [
        "wipedown.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{ae447fdf-037e-47c3-83e1-e327d9f0ba36}"
    }
  }
}