Examine source code of Focus Timer Fun

{
  "manifest_version": 2,
  "name": "Focus Timer Basic",
  "version": "1.0",
  "description": "Focus Timer (a timer to help users focus on studying and working, with short breaks), we can use Pomodoro Technique. This is a time management technique in which users work for 25 minutes and take a 5 minute break. After 4 work sessions, users will take a longer break (15-30 minutes).",
  "permissions": [],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "images/focus-logo.png"
    }
  },
  "icons": {
    "128": "images/focus-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e24f3b8d-458f-42b1-8de3-ee7f624a8dbd}"
    }
  }
}