Examine source code of Focus Timer itt

{
  "manifest_version": 2,
  "name": "Focus Timer",
  "version": "1.0",
  "description": "A simple Pomodoro-style timer to boost your productivity.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fb61c441-7246-4aed-a35d-1e6534390f38}"
    }
  }
}