Examine source code of Simple Site Blocker

{
  "manifest_version": 2,
  "name": "Simple Site Blocker",
  "version": "0.1.0",
  "description": "Block websites easily. Stay focused.",
  "author": "Bartlomiej Tadych",
  "homepage_url": "https://github.com/b4rtaz/simple-site-blocker",
  "developer": {
    "name": "Bartlomiej Tadych",
    "url": "https://github.com/b4rtaz"
  },
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_title": "Simple Site Blocker",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "64": "icons/icon-64.png",
      "96": "icons/icon-96.png",
      "128": "icons/icon-128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "b4rtaz@gmail.com",
      "strict_min_version": "57.0"
    }
  },
  "background": {
    "scripts": [
      "api.js",
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "blocked.html",
    "blocked.css",
    "blocked.js",
    "api.js"
  ],
  "permissions": [
    "tabs",
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ]
}