Alternativ till Airborn för Firebase med gratis licens

• Firebase
  Alla plattformar Windows Mac Linux Chrome OS Android iPhone iPad Android Tablet Kindle Fire Web Self-Hosted Software as a Service (SaaS) JavaScript BSD Windows Mobile Java Mobile PortableApps.com Chrome Microsoft Office Excel Cloudron Etherpad Firebase
• Gratis licens
  Eventuell licens Gratis licens Open Source-licens Kommersiell licens