Examine source code of ExLinks

{
  "manifest_version": 2,
  "name": "ExLinks",
  "version": "2.1",
  "description": "Extract all available download link in a page and show in a html page to use that easily",
  "icons": {
    "48": "Icon/url-extractor.png"
  },
  "browser_action": {
    "default_icon": "Icon/url-extractor.png",
    "default_popup": "index.html",
    "default_title": "Extract Links"
  },
  "background": {
    "scripts": [
      "Scripts/bg.js"
    ]
  },
  "permissions": [
    "storage",
    "webRequest",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "Scripts/content.js"
      ]
    }
  ]
}