Examine source code of ClockTrack

{
  "description": "A simple time tracking tool wich reads out tocket ids from the url.",
  "manifest_version": 2,
  "name": "ClockTrack",
  "version": "1.7",
  "homepage_url": "https://www.ftue.ddnss.org",
  "icons": {
    "48": "icons/48.png"
  },
  "permissions": [
    "activeTab",
    "clipboardWrite",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "clocktrack@www.ftue.ddnss.org"
    }
  },
  "browser_action": {
    "default_icon": "icons/32.png",
    "default_title": "ClockTrack",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html"
  }
}