Examine source code of Tab-Stop

{
  "manifest_version": 2,
  "name": "Tab-Stop",
  "version": "1.0",
  "description": "Stop view some websites which distruct you",
  "icons": {},
  "permissions": [
    "storage",
    "tabs",
    "notifications"
  ],
  "background": {
    "scripts": [
      "tab.js"
    ]
  },
  "browser_action": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{31893a11-8274-4a55-9c05-909ecea62ac1}"
    }
  }
}