Examine source code of clout

{
  "manifest_version": 2,
  "name": "clout",
  "version": "0.1",
  "description": "Removes quantitative feedback from Twitter.",
  "icons": {
    "48": "icon-48.png",
    "96": "icon-96.png",
    "512": "icon-512.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "permissions": [
    "tabs",
    "activeTab",
    "https://www.twitter.com/*",
    "https://twitter.com/*",
    "webNavigation"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.twitter.com/*"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "toolbar-icon-16.png",
      "32": "toolbar-icon-32.png"
    }
  }
}