Examine source code of Relaxation Timer

{
  "manifest_version": 2,
  "name": "Relaxation Timer",
  "version": "1.0",
  "description": "Set relaxation timers to take breaks between study or work sessions.",
  "permissions": [],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "images/relax-logo.png"
    }
  },
  "icons": {
    "128": "images/relax-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c42fae61-9d6c-4d44-ba26-b72e32caf25b}"
    }
  }
}