Examine source code of Distraction_Blocker

{
  "manifest_version": 2,
  "name": "Distraction_Blocker",
  "version": "1.0.0.2",
  "description": "Blocks access to URLs with user-provided REGEX patterns",
  "icons": {
    "48": "icons/hourglass_transparent.png"
  },
  "permissions": [
    "storage",
    "webNavigation",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/hourglass_transparent.png",
    "default_title": "Distraction Blocker",
    "default_popup": "popup/settings.html"
  },
  "background": {
    "scripts": [
      "background_scripts/filter.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e1cae6f-9516-46cd-8c81-9fb8eb531a4c}"
    }
  }
}