Alternativy k SlideMail pro Haiku s bezplatnou licencí

• Haiku
  Všechny platformy Windows Mac Linux Chrome OS Android iPhone Apple Watch Android Wear iPad Android Tablet Windows S Web Self-Hosted BSD Haiku PortableApps.com Slack F-Droid Chrome Ruby Gmail Cloudron Amazon Echo (Alexa Voice Service) PureOS (Purism)
• Bezplatná licence
  Jakákoli licence Bezplatná licence Licence Open Source Komerční licence