Examine source code of linkchat Calendar Add-on

{
  "description": "__MSG_appDesc__",
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "default_locale": "en",
  "version": "1.3.1resigned1",
  "homepage_url": "https://linkchat.io",
  "icons": {
    "16": "icons/icon-16x16.png",
    "48": "icons/icon-48x48.png",
    "128": "icons/icon-128x128.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48x48.png",
    "default_title": "linkchat",
    "default_popup": "popup/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3ef085b0-fe60-112f-8cff-0800200c9a66}"
    }
  }
}