Examine source code of Save to ISELO

{
  "short_name": "Save to ISELO",
  "name": "Save to ISELO",
  "description": "Browser Extension to save content to ISELOApp.com",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "version": "1.3.0",
  "manifest_version": 2,
  "browser_action": {
    "default_popup": "index.html"
  },
  "background": {
    "scripts": [
      "static/js/browser-polyfill.js",
      "static/js/background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{261cca2e-6609-4a85-aee6-2d168e941d18}"
    }
  },
  "externally_connectable": {
    "matches": [
      "http://web.iseloapp.com/*",
      "https://web.iseloapp.com/*"
    ]
  },
  "permissions": [
    "activeTab",
    "identity",
    "storage",
    "http://api.iseloapp.com/",
    "https://api.iseloapp.com/"
  ]
}