Examine source code of Dark Theme for Twitter

{
  "name": "Dark Theme for Twitter",
  "short_name": "dtftwitter",
  "description": "Turn dark theme for Twitter on and off the easy way",
  "author": "James Fray",
  "version": "0.1.2resigned1",
  "manifest_version": 2,
  "permissions": [
    "storage",
    "tabs",
    "cookies",
    "*://*.twitter.com/*"
  ],
  "background": {
    "persistent": false,
    "scripts": [
      "common.js"
    ]
  },
  "homepage_url": "http://add0n.com/dark-theme.html?from=twitter",
  "icons": {
    "16": "data/icons/16.png",
    "48": "data/icons/48.png",
    "128": "data/icons/128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "data/icons/16.png",
      "32": "data/icons/32.png",
      "64": "data/icons/64.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitter.com/*"
      ],
      "js": [
        "data/inject.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "options_ui": {
    "page": "data/options/index.html",
    "chrome_style": true
  },
  "applications": {
    "gecko": {
      "id": "{0da55247-9d34-44dc-8f7a-00d093abdedf}",
      "strict_min_version": "52.0"
    }
  }
}