Examine source code of Dumb Smartschool

{
  "manifest_version": 2,
  "name": "Dumb Smartschool",
  "description": "Make Smartschool cooler by adding a lot of hacks!",
  "version": "0.7.2",
  "permissions": [],
  "content_scripts": [
    {
      "js": [
        "index.js"
      ],
      "matches": [
        "*://*.smartschool.be/*"
      ]
    }
  ],
  "icons": {
    "48": "icon.png",
    "96": "iconX2.png"
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7c0da18a-8a2f-4975-b443-545d6cb70899}"
    }
  }
}