Examine source code of Window Session Saver

{
  "manifest_version": 2,
  "name": "Window Session Saver",
  "version": "0.6resigned1",
  "description": "Saves the window tabs so that they could be used later.",
  "homepage_url": "https://github.com/Erick2206/Window_Session_Saver",
  "icons": {
    "48": "icons/session_saver_icon.png"
  },
  "permissions": [
    "*://developer.mozilla.org/*",
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/session_saver_icon.png",
    "default_title": "Session Saver",
    "default_popup": "popup/save_extension.html",
    "browser_style": true
  },
  "applications": {
    "gecko": {
      "id": "{ad340fe3-d3ff-417b-a765-ecfad542cd0c}",
      "strict_min_version": "57.0"
    }
  }
}