Examine source code of Pomodoro timer

{
  "manifest_version": 2,
  "name": "Pomodoro_timer",
  "version": "1.2",
  "author": "K034K",
  "homepage_url": "https://github.com/K034K/pomodoro_timer",
  "description": "Add a pomodoro timer to the browser.",
  "icons": {
    "48": "icons/pomodoro-48.png"
  },
  "browser_action": {
    "default_icon": "icons/pomodoro-32.png",
    "default_title": "Pomodoro Timer",
    "default_popup": "popup/pomodoro_timer.html"
  },
  "permissions": [
    "notifications",
    "storage"
  ],
  "background": {
    "scripts": [
      "/background/background.js"
    ],
    "persistent": true
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pomodoro_timer@pomodoro_timer.com",
      "strict_min_version": "42.0"
    }
  }
}