Examine source code of TwitterImageDownloader

{
  "description": "Help you to download images from twitter timeline",
  "manifest_version": 2,
  "name": "TwitterImageDownloader",
  "version": "2.1.0",
  "homepage_url": "https://github.com/Eivy/TwitterImageDownloader",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "TwitterImageDownloader",
    "default_icon": {
      "16": "icon16.png",
      "32": "icon32.png"
    }
  },
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "storage",
    "webRequest",
    "*://*.twitter.com/*"
  ],
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  }
}