Examine source code of MailMess

{
  "manifest_version": 2,
  "name": "MailMess",
  "version": "1.41",
  "description": "MailMess - A firefox extension for generating masked emails",
  "icons": {
    "192": "static/logo192.png",
    "512": "static/logo512.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "MailMess"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bc860d9f-a21a-4b3a-815a-162cb848badb}"
    }
  }
}