Examine source code of LinkHubble

{
  "applications": {
    "gecko": {
      "id": "link.addon@performics.com",
      "strict_min_version": "60.0"
    }
  },
  "minimum_chrome_version": "54",
  "manifest_version": 2,
  "name": "LinkHubble",
  "version": "1.0.13",
  "description": "LinkHubble searches for you after external links and links of interest!",
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/browser-polyfill.min.js",
        "js/content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "js/browser-polyfill.min.js",
      "js/background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "icons/logo_on.png",
      "32": "icons/logo_on.png"
    },
    "default_title": "LinkHubble",
    "default_popup": "index.html"
  },
  "web_accessible_resources": [
    "images/*.png"
  ],
  "permissions": [
    "<all_urls>",
    "activeTab",
    "tabs",
    "storage"
  ]
}