Examine source code of AOtoolbar

{
  "manifest_version": 2,
  "name": "AOTool",
  "description": "Thomas More Research Tool | Concept & Content: Alex Wuyts | Coding & Design: Fatjon Zariqi & Hamza Raja & Brent Rutten",
  "version": "2.4.3",
  "icons": {
    "64": "img/64_icon.png",
    "128": "img/128_icon.png",
    "512": "img/512_icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "img/512_icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "aotoolbar@thomasmore.be"
    }
  }
}