Examine source code of Caged Twitter

{
  "manifest_version": 2,
  "name": "Caged Twitter",
  "version": "1.0",
  "description": "Remove Twitter Recommendations. Makes the \"Following\" feed on Twitter the default feed, and hides the \"For you\" feed.",
  "icons": {
    "16": "assets/icon-16.png",
    "32": "assets/icon-32.png",
    "48": "assets/icon-48.png",
    "128": "assets/icon-128.png"
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://twitter.com/*",
        "https://mobile.twitter.com/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1bf4127b-a93e-4b4c-974e-61bf3044b70a}"
    }
  }
}