Examine source code of Simple Blocker

{
  "description": "Block URL using regular expression",
  "manifest_version": 2,
  "name": "Simple Blocker",
  "version": "0.3.8resigned1",
  "author": "Ery Widyanto",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "backgrounds/main.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "icons": {
    "48": "icons/icon.png",
    "96": "icons/icon@2x.png"
  },
  "applications": {
    "gecko": {
      "id": "simpleblocker@ery.my.id",
      "strict_min_version": "51.0"
    }
  }
}