Examine source code of BlocksEverything

{
  "manifest_version": 2,
  "name": "BlocksEverything",
  "version": "1.1",
  "description": "Block distracting websites during focus hours",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "<all_urls>",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_title": "Toggle BlocksEverything",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "settings.html",
    "open_in_tab": true
  },
  "icons": {
    "48": "icons/1.png",
    "96": "icons/1.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4db26086-e8c2-4f81-8cc8-dffe56d5d377}"
    }
  }
}