Examine source code of Hide Twitter Followers

{
  "manifest_version": 2,
  "name": "Hide Twitter Followers",
  "version": "1.0",
  "description": "Hide all the follower counts on twitter.com",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "applications": {
    "gecko": {
      "id": "stefanjudis@gmail.com"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*",
        "https://mobile.twitter.com/*"
      ],
      "js": [
        "no-followers.js"
      ]
    }
  ]
}