Examine source code of Safe Surf

{
  "manifest_version": 2,
  "name": "Safely",
  "version": "1.0",
  "description": "Automatically closes every active tab containing explicit sexual contents. This works by continuosly searching for vulgar word from a list of vulgar words popularly associated with explicit sexual contents.",
  "icons": {
    "48": "icons/safely_48.png",
    "96": "icons/safely_96.png"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "find",
    "alarms",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4c5356e8-a63c-4ee2-9e3a-62f1ef5ddcaa}"
    }
  }
}