Examine source code of BlockOn

{
  "manifest_version": 2,
  "name": "BlockOn",
  "version": "1.3",
  "description": "Choose which network you can browse",
  "icons": {
    "32": "icon32.png",
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon32.png",
    "default_title": "BlockOn",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{053278c2-7f71-427e-81d4-598bc3b58f3d}",
      "strict_min_version": "128.0"
    }
  }
}