Alternativ till MTcaptcha för Android med gratis licens

• Android
  Alla plattformar Windows Mac Linux Android iPhone Windows Phone iPad Android Tablet Web Self-Hosted Software as a Service (SaaS) PHP Wordpress Joomla .NET Framework ASP.NET Drupal Drupal Commerce ASP.NET MVC JSP MyAdmin JSP/MySQL Administrador Web
• Gratis licens
  Eventuell licens Gratis licens Open Source-licens Kommersiell licens