Mass follow for Twitter

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Mass follow for Twitter",
  "version": "17",
  "minimum_chrome_version": "49.0.0.0",
  "description": "A feature-rich extension to mass follow and unfollow on Twitter.",
  "homepage_url": "http://www.clemensteichmann.com/mass-follow-for-twitter.html",
  "author": "Clemens Teichmann",
  "permissions": [
    "storage",
    "https://twitter.com/*",
    "unlimitedStorage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "js": [
        "class_list.js",
        "extension.js"
      ],
      "css": [
        "extension.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "extension.html"
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  }
}