Examine source code of Time Tracker

{
  "manifest_version": 2,
  "name": "Time Tracker",
  "version": "1.0.0",
  "description": "A lightweight Firefox extension that records how much time you spend on websites with a quick popup, an options page for settings and data management, and a dashboard for time by site.",
  "permissions": [
    "tabs",
    "storage",
    "notifications",
    "idle"
  ],
  "icons": {
    "48": "assets/icons/icon-48.png",
    "64": "assets/icons/icon.png"
  },
  "background": {
    "scripts": [
      "js/shared/functions.js",
      "js/shared/Storage.js",
      "js/shared/MessageManager.js",
      "js/background/TabManager.js",
      "js/background/MessageInterface.js",
      "js/background/Background.js",
      "js/background/bootstrap.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "48": "assets/icons/icon-48.png",
      "64": "assets/icons/icon.png"
    },
    "default_title": "Time Tracker",
    "default_popup": "popup/popup.html"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "time-tracker@github.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}